I've heard them say things like that in real world. Once they get the impression that it is socially acceptable to repeat those things, they would.

It is the same with things like "negging". Once they decided that making not so subtle digs at women while supposedly flirting, they started doing it. Then they became angry because women don't like people making digs at them and the tactic doesn't work the way they want it.

People in the internet is real people shielded by anonymity. I've two very sexist uncles that are like this. I'm not even surprised that they jumped in the manosphere because they were always like that. They just needed an excuse to be open about who they are.