Cause that's all they are - tropes. stereotypes. They're the same stereotypes that we're recognizing as harmful expectations. When we say "men are expected to be X" that's the same thing - the reason we're expected to be X is because "you need to be X or you're not a real man."
We feel the ways in which society's stereotype of men hurt us, and those same expectations cause harm to other folks as well. It's fair for folks to complain about that, but it's complaining about the stereotypes.
The left wants to change toxic gender roles, just like we do. Do you have better ideas for actually getting things to change that doesn't involve the left? We can complain about society all day long, but actually changing it requires work. The door is open for you to join the fight and take part in the conversation - it just requires solidarity and a willingness to fight for others too.