There are two different questions here: (1) Why did Hitler hate the Jews? and (2) Why all of the Jews, not just some of them were the subjects of Hitler's anger?
Question (2) is much easier to answer, namely, Hitler hated all Jews because he felt that Jews were conspiring together to cause all the issues he hated the Jews for. He did not see different Jews as having different perspectives, but rather that all Jews believed the same things and were the same physical race.
Question (1) is much more complicated....
Hitler provided numerous rationales during that period as to why he believed that the Jews were worthy of hate. However, the only person qualified to answer this question fully and accurately, without speculation, (Hitler) killed himself on April 30, 1945. Various contributors have stated that the following were some of the reasons that Hitler claimed to hate the Jews:
1) Superiority of the German People: Hitler believed that the Germans as a "race" of Nordic of peoples were superior in all ways to all non-German people. Since the Jews were not a Nordic people, Hitler reviled them (as he reviled the Romani, Slavs, and other ethnic minorities).
2) Decay of the German State: During the 1800s, Jews began to become more integrated in German National Life. They served in its government, its military divisions, and its industry. As was typical of Western Europe, the Jews had more of a hand in the higher echelons of government than their population percentage would account for. The Nazis saw this increasing Jewish percentage in the government as a slow takeover of German policy and a corruption of the German people. They contrasted the great victories under Bismarck with the depressing failure of World War I and noted how a much larger percentage of soldiers in the latter war were Jewish. There was also the sentiment than in the early 20th century, values were beginning to ebb (this is similar to current politics in the United States) and the Jewish integration in the German apparatus (becoming teachers, lawyers, doctors, etc.) was to blame for this recession of values as opposed to modernity as a process.
3) Nationalism: Germany was brought together under the Nationalist conception that all peoples with German culture, history, and language should be united regardless of which principality currently held control. The German self-conception also had an ethnic component, holding that the perfect German was blond and blue eyed. Regardless of the fact that the majority of Germans were dark haired, Jews stuck out like a sore thumb because they overwhelmingly had darker hair. In addition, the idea of a German Jew was still rather new and both Jews and non-Jews tended to see the Jews in Germany as being part of a vast Jewish network and that these Jews just happened to be in Germany. The Nazis capitalized on this cosmopolitan sensibility by claiming that Jews' allegiances were not to the German State, but to secret Jewish Councils organizing world events.
4) Economy: Whether it was true or not, there was perception among Germans and the Nazis in particular that Jews were wealthy individuals and had a higher per-capita income than the Germans. In many ways (because of the above two reasons) Germans felt that the Jews were "stealing" their money while they were poor and suffering. Adolf Hitler blamed the Jewish population for the social and economic problems of the era. A popular anti-Semitic belief was that Jewish families were shrewd and sought to control the wealth of a community at the expense of other members in the community. This being the case he thought that the world would be a better place if the Jews were no longer in charge of finance.
5) Pseudo-Science: The late 19th and early 20th century was filled with radical new ideas concerning Social Darwinism. It was believed by the Pseudo-Scientific community (which was rather in vogue) that different groups of people or races exhibited different emotional traits that were linked to physical differences. This led to the belief that Jews were corrupt and thieving by their irreversible nature and that they could not be "cured" and brought up as proper Europeans. This formalized Racial Anti-Semitism in Germany and made the situation much more dire for German Jews.
6) Heresy/Christian Anti-Semitism: Although not as much an issue in World War II as it may have been 500 years prior, Jews were still considered the heretics who murdered the LORD and Savior. This helped to justify Anti-Semitism as the Jewish comeuppance for their accepting of the "Christ Bloodguilt". Jews were called Christ-killers by the Nazis, as they had by most Christian churches for centuries, and that was behind a lot of the hatred. This existed regardless of the fact that the Bible names the Jews as God's Chosen people first.
7) Hitler's Ambition: Adolf Hitler was very ambitious. His dream was to see Germany at the top. After the First World War he became more and more ambitious. He blamed the Jews for the misery and suffering of Germans. Moreover, he held Jews responsible for the loss of World War I. He claimed that they held high position and were very rich. This was one of reason for his hatred for the Jews.
8) Populism: Adolf Hitler's "hatred" of the Jews was one of the tools he used to convince the people of Germany that he knew the source of their economic problems and that he was the person who could correct the situation. He chose to use the long standing antisemitism in Germany to gain the people's support.
9) Anti-Semitic Childhood: When Hitler was studying Art in Munich as a teenager he was rejected from the academy he wished to attend and for some reason, he blamed it on the city's Jewish population. He was also brought up in an anti-Semitic family (at least some believe).
10) Foreigners: Hitler argued that the German Jews were not 'native' members of the country and should not be able to enjoy the benefits of citizenship. Their motives would be suspect as their loyalty was to something other than Germany. (Of course, this argument has been used against all minorities and is equally fatuous as concerns the Jews.)
11) Communism: Hitler alleged that the Jews were the primary supporters of Communists and thus also considered them in bed with his political opposition. (It should be noted that there is NO credible evidence the Jews were the main supporters of Communism, and this is yet another stereotype used by bigots for decades.)