Why do some people over-generalize that "women can't handle casual"?

I'm just so tired of seeing this on the dating subs. Like have ya'll SEEN some of the men that are open to short-term fun/flings? Like don't worry, they don't ever have to worry about a woman liking them.

I just hate this stupid generalization because I've seen this BOTH ways. I've seen guys too in casual/fwb situations who purposely won't "open up" or talk about other things because they don't wanna catch feelings or whatever. It's not just girls. It's annoying and I know that some of the people who say this get off on thinking that way.

Also, another pet peeve is that you can't say ANYTHING about your casual situation/fwb because if you ever "expect" anything from them, then that clearly means you want them cuz you're not allowed to have any sort of standards and have to accept even being treated like crap just because "iT'S CaSuAL"? Thank you for your answers.