I think just because someone faces discrimination and oppression doesn't always stop them discriminating or oppressing. Misandrists calling themselves feminists hold discriminatory views about men. I find that sadly ironic. Black men holding discriminatory views about gay men or women happens. I can't say all feminists hate men, because I don't. I can't say all black people hate gays, because they don't. But what this illustrates is that hatred based on a set of factors does not come from people who have no discrimination to face. Everyone does (have to face it in some way), and most people do not use that to open their own mind and see intolerance they face as a force to clean out the cupboards of their own misguided hatred, it fuels the fire of anger at being opressed in some way and directs it at another group. That being said, "all gays, all black people, all muslims all women indeed all <insert any oppressed group here>" could use what they face to open up an understanding and empathy with others who face it.
