In Orot, Rav Kook basically says: Eretz Yisrael is an end, not a means. In Nineteen Letters, Rav Hirsch says the opposite, that Eretz Yisrael is merely a means and not an end. Shabang - contradiction!
But wait, not so fast! Let's check the contexts! For Rav Kook, an "end" (which Rav Kook endorses) means integral to Judaism, while "means" (which he criticizes) means a utilitarian tool which could be conceivably dispensed with. In particular, Rav Kook criticizes those who see Eretz Yisrael as a convenient place for the nation to be strengthened by physical gathering; if this were the purpose of Eretz Yisrael, then conceivably a substitute could be found, whether in Uganda or in a Hebrew University.
But for Rav Hirsch, "end" (which he criticizes) means idolatrous fascist nationalism as its own value (see his comments on the Tower of Babel), while "means" (which he endorses) means that it is an essential part of Torah. Rav Hirsch's "means" is identical with Rav Kook's "ends"!
Rav Hirsch, in criticizing the understanding of Eretz Yisrael as an "end", is writing against the nation-state being worshipped in and of itself, as its own value; think Nimrod and the Tower of Babel, and Machiavelli. Would you one dare say that Rav Kook, in his supposed disagreement with Rav Hirsch (holding Eretz Yisrael to be an "end"), means to say that Nimrod and Machiavelli are Toraitic?! Furthermore, Rav Kook himself, elsewhere in Orot, says one of the blessings of galut is that we were spared having to hold political power in the era of Roman Machiavellian politics! Thus, to posit a disagreement between Rabbis Hirsch and Kook here is to create an internal contradiction within Rav Kook!
Kook: End = essential for Judaism, means = dispensable and not required (think Uganda);
Hirsch: End = fascism, means = essential for Judaism
Thus, Rav Kook's "end" is the same as Rav Hirsch's "means"; the two actually seem to agree more than they disagree. Furthermore, since Rav Kook himself criticizes Machiavellian Roman politics (the same as Rav Hirsch's "end", which Rav Hirsch rejects but which Rav Kook supposedly endorses), to say that Rav Kook disagrees with Rav Hirsch here is to make Rav Kook internally contradictory.
Thus, Rabbi Bezalel Naor's edition of Orot quite rightly points out that Rav Kook is replying to cultural Zionism and the Ugandists, that Eretz Yisrael is convenient and helpful but not essential.
And according to Rabbi Yehiel Weinberg (from Dr. David Kranzler and Rabbi Dovid Landesman, Rav Breuer: His Life and Legacy - A Biography of Rav Dr. Joseph Breuer, p. 212, here),
The complaint against Hirsch that he negated the national ideal of the Jewish people is absurd. A religious philosophy which places the people of Israel in the center of its thought and which sees Israel as the axis around which world history revolves - could there be any nationalism greater than this? Hirsch was certainly opposed to secular nationalism based on the hollow and empty foundation of race and common suffering. Such a nationalism is alien to the Jewish spirit, for it is borrowed from the language of other nations and it falsifies our unique historical ideal. The nationalism of Hirsch is religious and ethical; such a nationalism is not concerned with hatred and conquest.In other words: Rav Hirsch was not opposed to nationalism per se, but only to that nationalism which was parochial and chauvinistic and militant, seeing such nationalism as idolatrous (see again his comments on the Tower of Babel). Rav Hirsch would also likely disagree with Rabbi Moshe Shmuel Glasner's Zionism in the Light of Faith, when Rabbi Glasner said,
However, then as now, my position was this: even if we should admit that emancipation and reciprocity contain within them certain dangers for complete faith, this presumption cannot serve as a reason to ascribe to the people an intention to forego, or even to reject, natural rights. "Her ways are the ways of pleasantness," not the ways of unnatural rejection. The Holy One Blessed Be He does not demand of people to cease being people, nor does He demand of them that they quell their ambitions for success in anticipation of dangers that are liable to endanger the completeness of their faith.Rav Hirsch, if I am not mistaken, would reject any claims predicated on the Jewish people being a "people" and deserving of the same things all people do. That is, some will say that all people deserve a land, including the Jewish people, but Rav Hirsch will reject this. This is actually incredible, given that the entire basis of Mensch Yisroel and Torah im Derekh Eretz is nothing other than the fact that Jews are people. They are even people prior - ontologically and chronologically - to their being Jewish. (See Rabbi Shelomo Danziger, "Rav S. R. Hirsch - His תורה עם דרך ארץ Ideology", in Living Hirschian Legacy, here.) But this is Rabbi Hirsch's position, agree with it or not.
The only significant and greatly meaningful difference between Rabbis Kook and Hirsch here is whether the importance of the land of Israel is rational or mystical, i.e. Maimonidean or Kuzarian (cf. Professor Menachem Kellner's Maimonides' Confrontation with Mysticism) - does the land of Israel contain inborn metaphysical significance, or is its importance physical and temporal? But that's it.
Rav Tzvi Yehuda points to a second contradiction: Rav Kook says galut is bad, Rav Hirsch says it is good! But not so fast; Rav Hirsch never says this! Rav Hirsch, in his essay "Av I", dwells at length on how the galut is a tragedy, how the galut shekhina means G-d has lost His national manifestion and vehicle for the representation of the Torah on every level of national life. (I dare you to tell me how this differs from Rav Kook!) All Rav Hirsch says in Nineteen Letters is that bedieved (after the fact), there is value in the galut, but the galut is a tragedy nonetheless. And guess what? The Gemara in Pesahim seems to say the same thing, that we were exiled for the sake of gathering gerim. So maybe Orot is writing against the Gemara, not Rav Hirsch! And on top of that, Rav Kook, elsewhere in Orot, says there is an inner value in the galut, that in the Machiavellian world of Roman politics, we didn't have to rule - Rav Kook sees good in the galut! The only other person I've seen say this is Rabbi Dr. Eliezer Berkovits, in his Crisis and Faith, Towards Historic Judaism, and Between Yesterday and Tomorrow. (Rabbi Berkovits goes a bit further than Rav Kook; Rav Kook said this positive value of galut is bedieved, a post-facto comfort for us, while Rabbi Berkovits says it is the very reason for the galut in the first place, that Caesaria and Jerusalem could not stand together simultaneously, as the Gemara says.) So actually, Rav Kook perhaps sees more good in the galut than Rav Hirsch does! Thus, Rabbi Bezalel Naor says that Rav Kook's target for criticism is not Rav Hirsch, but rather Hermann Cohen, who saw the galut as a positive step upwards from vulgar nationalism and parochialism.
So much for Orot criticizing Rav Hirsch. The problem really is that no one actually reads Rav Hirsch. The academics assume he is a German gentile masquerading as a rabbi, and so they assume Kant is his source even when an explicit mishnah in Avot preceded Kant. (See Rabbi Joseph Elias's edition of Nineteen Letters, and Rabbi Shelomo Danziger's reply to Rabbi Howard I. Levine in Tradition.) And the Haredim assume he is haredi and holds by Daas Torah (even though Rabbi Hirsch's essay "Jewish Communal Life" is a masterpiece of constitutional-democratic theory that reads almost like John Locke, if I may exaggerate just a little bit, but not very much), and so they (the Haredim) also never read him. Everyone says the most ridiculous garbage in Rav Hirsch's name, things that are disproven by even a cursory glance at his own words. Rav Hirsch was a Spanish Jew - Muslim or Christian Spain, take your pick - in German clothing. That's it.
Speaking of Rav Hirsch's essay "Jewish Communal Life", the entire essay describes how the Jewish community is a microcosm of the Jewish nation. Throughout Rav Hirsch's writings is a famous emphasis of the traditional kehilla, and the whole time, the underlying assumption by him is that the kehilla is a microcosm and representative of the nation. In galut, we tragically lack national manifestation in Eretz Yisrael, as Rav Hirsch says in "Av I", but every time Rav Hirsch mentions the kehilla, he is implicitly expressing his own form of nationalism.
Yes, Rabbi Hirsch pasqened the Three Oaths as halakhah, and said that the galut would not end until we did teshuva for our sins. Yes, this is a contradiction with Rabbis Tzvi Hirsch Kalischer and Yehuda Alkalai and Rav Kook, absolutely. But this is something entirely else. If one wants to draw a distinction between Rabbis Kook and Hirsch based on mysticism versus rationalism, or based on the halakhic nature of the Three Oaths, then please, by all means. But don't misread Rav Hirsch and then mistake Rav Kook for criticizing Rav Hirsch when he was really criticizing Herzl, Ahad ha-Am and Hermann Cohen.
Similarly, people will say that Zionism began with Herzl. But in truth, people like Dona Nasia and Rabbi Haim Abulafia were already settling Teveria, Rabbi Yaakov Beirav tried to reinstitute semikha and the Sanhedrin, and Lurianic Qabalists believed their practices repaired the cosmos and brought geula closer. Their methods were different than those of the Zionists, but Rabbi Yehuda Alkalai (of Sarajevo)'s departure from the tradition of the Hida (Rabbi Haim Yosef David Azulai, the teacher of Rabbi Eliezer Papo, in turn Rabbi Alkalai's teacher) was not his love for Eretz Yisrael and his efforts towards geula per se, but only that he substituted Qabalistic theurgy with practical politics and agriculture. But both Rabbis Alkalai and Azulai took practical steps, in their own ways, towards geula.