I believe that some men don't like Michael because he had a rather androgynous image, which would make some people uncomfortable and willing to believe anything about him. And there is also that eternal prejudice, that they don't think that a "real man" wants to be with children (except maybe if they're family). It is more likely to them that a man would abuse boys than that he would want to be their friend... So there's no reason for these people to do any research. Michael was never a "real man" in their eyes, so that gives them the "right" to assume anything about him.
One guy on a Swedish forum even said that Michael should have slept around with lots of different women, because that would have been "normal". Even if these women would have accused him of sexual assault later, it would have been better than spending time with young boys in a totally harmless manner. Because it would have been more "normal"... I decided to not reply anymore to this loser, but he did give me a glimpse into how the haters must be thinking. It is terrible though that a hater would go so far as punching a MJ fan on the lip. Then again, such a thing just proves what kind of pathetic people we're dealing with...