I feel like women don't really grasp just how little respect people have for one another in general.
Aggressive people aren't seen as leadership material by anyone who knows anything about leadership. Aggressive people make too many impulsive decisions and usually cause division and strife in the ranks.
That guy isn't being called a dickhead because pushing up on some hyper-aggressive dude's masculinity is a good way to escalate a fight - so you just don't do that, especially with guys you're not friends with or close to. So you just kind of keep those thoughts to yourself and move on.
Aggressive women aren't typically seen as a physical threat, so they get shit-talked.
Assertive people may or may not be seen as leadership material. Depends on if they get results or know what they're talking about. And yeah, as someone that's dated a few different women with strong personalities, I'm aware that it's much harder for them to get meaningful respect in the workplace - but it's not like guys are just handed respect either.
If you're a guy, most people do not give a shit what you think or what you have to say unless it somehow benefits them. Women that you're vulnerable with will use that against you. Men will just kind of hmm and haww and move on to something else as quickly as possible.
I've heard that "men don't respect women" over and over and over. But I think the truth is that very few people genuinely respect anyone else at all. At least that's been my observation in life.