That's part of it though!
You're right, men ARE told to make the first move. We are taught to be aggressive, to chase after girls, to treat sex as conquest, etc. That's why the discussion is important. A lot of feminists/progressives are trying to change/remove these gender roles, because it reinforces so much bad behavior. What may seem confident and assertive in a man's mind can come off aggressive, weird, creepy, to another person.
I think there is a fairly clear distinction between what is rape and what is not rape. But there is a whole spectrum of sex when it comes to whether it's "good" or "bad" or "awkward" or any number of things. And the societal dynamics between different sexes is a large part of it. Many men don't want to feel vulnerable, so they don't communicate what they really want. And many women feel like they need to be accommodating, so they go along with shit they don't enjoy.