The dictionary fallacy. What matters is not what the "official" definition of feminism is, but what feminism actually is; and in the real world, feminists hate men. Therefore, feminism is a hate movement. I'll change my mind when feminists stop trying to hurt men and start helping them (but they'll never do that, because their whole philosophy can be reduced to "men are the problem").
That's not my personal experience with feminists. It is a fallacy to apply a definition over evidence, but that's not what I am suggesting. I am suggesting that in order to speak of a group in a meaningful way, you need to define that group in some manner. It is also fallacy to generalize your own experience as a definition, especially when it runs counter to that of others. I can imagine that you have had a certain kind of experience with feminists, but your experience is different than my own. To me, it's not surprising. Every 'ism' that is widely practiced and espoused is muti-faceted and has contradictory elements. It's human nature.