As a black guy I don't remember a friend ever saying "black people suck" to my face. But I've heard people I'm close with, both women and men, say that "men suck" countless times. I think a lot of people who don't see themselves as "biased" still carry a lot of bias when it comes to gender, and it has an impact.
Misandry is normalized in society. Whenever you encounter a baseless attack on men just reverse the roles and you'll realize that there'd be pitchforks for treating women as anything other than paragons of virtue. Entire entertainment genres are built around portraying men as inept fools who can be looked down upon by the opposite sex. Seinfeld is one of the few sitcoms where a female character is as flawed as the me…
To that point, culture is absolutely full of baseless attacks on women too, often in a far more damaging context. Lots of people still feel way too comfortable suggesting women are biologically unsuited for high status jobs and really only valuable for making babies. And the vitriol directed at women in the abortion debate, and the actual reduction in rights that rhetoric has led to, sort of puts dumb male sitcom characters in perspective.