Aziz Ansari Doesn't Pick Up On "Non-Verbal Cues" and Gets Treated Like A Rapist

[Mermaid]

Is this something everyone is capable of doing?

It's something everyone (excluding certain mental disabilities) is capable of learning to do.

Have you ever thought for a minute about why someone would feel unable to eject from a social situation like this?

Yes, I can think of various reasons. But what's the solution?

1. Such women avoid such situations and work on their assertiveness.

2. No man ever knows if what he's doing is acceptable until after the fact.

I think the first is more reasonable.

Of course people are capable of learning to communicate. That doesn't mean that a lot of women do not feel they cannot, or at least it is not clear at first that they can, for the reasons stated by Jack a few posts up. 
Your list is a tiny bit incomplete.