Re: "...Why do so many Jews become self-hating?..."
Speaking only of my own experience, I was told by virtually all of my teachers and classmates, beginning with the first grade, that Jews were Satan, Jews murdered G-d, Jews were not allowed, Jews were the cause of every trouble that ever existed on Earth, Jews stole money, Jews were Communists, Jews were traitors, Jews owned all the banks, Jews owned every newspaper and media outlet, Jews deserved the Holocaust because "they had ruined Germany", etc. etc..
With the advent of puberty, my friends from school told me that their parents had forbid them to ever socialize with Jews again, because it would destroy their "social standing".
Even in university class, a history teacher told the entire class that "America has a serious "minority" problem just like the Soviet Union"..."they call themselves 'Jews' ".
Too much of 'more of the same' to ever write it all down, and all of it within the country which has been better to the Jews than any other.
So, should it be a great wonder to non-Jews, that growing up in this setting somehow might convince a Jew that "he or she should not like themself"?