You're right, it was pretty off-topic.
Sexism is sexism regardless of who it comes from. I never said it comes primarily from women anyway. Even if it's coming from a man, it's still sexism. Would it be less sexist if women were discriminated against by other women? Nope. People who hate a certain gender are called misogynists (hate women)/misandrists (hate men).
Racism against white people is a thing. The world is more centered around ethnicity now, and while it isn't a bad thing, whites are generally becoming more underprivileged (if you read the second article, it talks about this extensively). Regarded, it doesn't overpower other racial issues; it's still real, however. Don't discount it.
Not angry about this or anything, but when people say male sexism isn't real, it bugs me because I've gone through it my whole life and I plan to advocate against it at some point. :P It helps to make sure as many people are aware of it as possible.