Agree you can't really ask if most men are arseholes and then attack posters who answer 'no'.
I sometimes get very depressed reading the threads on MN where a woman is being abused/mistreated and posters engage in minimising and gaslighting and essentially doing the abuser's job for them.
It also upsets me to see the posts where a woman's saying, "My DH does fuck all and can't even work the washing machine hahaha" and hundreds of women post about how hilarious it is that they too live with a pathetic lazy manchild.
However. It is self-selecting, isn't it? Women aren't going to post on here about their happy relationships. But on these threads you do always see women saying, "my partner would never treat me that way" and sharing their positive experiences to give perspective.
More men than women are "like that" I think - certainly the vast majority of violence is committed by men, and all of the rape. It's also more likely that men will be lazy and not do their bit when kids are involved, because women really can't opt out in the same way. But as far as affairs and cheating are concerned, it's both sexes who do this. And women can be unreasonable, controlling and nasty, too - they tend to be more abusive towards their children than their partners, though, and keep their partners on side, whereas men will more likely abuse both their partners and children.
So I think the answer to your question, OP, is no, it's not most men. But it is a depressing number of men, enough to make a significant impact on this forum, and definitely more men than women.