I can't speak for everyone here, but as a red pilled man, I am sure I can speak for quite a LOT of other red pilled men at least. Here is my theory:

First and foremost, we used to BE just like these so called male feminists. Perhaps we didn't call ourselves feminist per-say, but you can bet your bottom dollar feminism influenced and made us complete nice guy pussies (especially at delicate times of our lives, like high school, etc.)

I remember a time in high school when literally my friends were trying to push me to go and just TALK to a girl in the hallway by her locker. There was a girl in our group (whom ironically is now a big feminist, I've seen her facebook). I told them "Whats the point of approaching her? She'll probably just think since I'm a guy all I want is one thing and that I'm perverted anyway. Why bother?" I don't remember the EXACT word for word exchange, but that is the gist. Not helping my opinion at the time, the girl responded "Guys ARE perverted...". I am sure she was innocently joking at the time, and ironically I had seen her date the abusive asshole types. But I didn't take it that way. It only reaffirmed my opinion of myself: I was an oppressor of women and had no business approaching them, even in high school.

I was feminist minded. I didn't question what feminism was telling me about myself. I can tell you this: I know a lot of other men have shared my experience. I was basically a male feminist. I was too nice. I figured, maybe I can show women how much different I am from other guys and maybe they will see not ALL men are bad.

Nowadays male feminists remind me of my old self, and it disgusts me. I missed out on so much girls in high school throwing themselves at me because I didn't "want to offend them with my sexuality".

This is the thinking behind disliking male feminists, among other reasons like simply not agreeing with their theories about us being predators towards women. And one more thing:

Throwing other men under the bus who didn't necessarily do anything wrong, just for the chance at pussy is really fucking pathetic. They're lucky they aren't doing that shit in the ghetto, they'd be fucked.