What conclusions should we draw about Grace's painful date with Aziz Ansari?

I will take Grace's description of the events to be accurate, since Ansari did not contest them. What can we conclude from these events?

She went to his apartment expecting and intending some sort of sexual encounter, but as the encounter proceeded, she began to feel uncomfortable with it. After some time, she realized that she did not want to continue.

That is not unusual. When you "have a bad feeling about this", it often takes time for that to crystallize into "I'm not going there."

Grace first made gestures to hint at her unwillingness, which Ansari did not seem to recognize, and she rebuked him for that.

It is not valid to rebuke someone for "misreading" hints. A hint is a veiled form of communication. It is unfair to obscure a message and then rebuke someone for not understanding it. If you want someone to understand "no", say "no". (Eventually she did.)

On the other hand, he might have understood her feelings if he had cared about them. It is clear for many reasons that he didn't care. Ansari was selfish and inconsiderate throughout the date.

He pressured her persistently for penetration. Apparently that particular act was more important to him than her pleasure, or her contentment. He acknowledged that they could only continue in sex if she too were "having fun", but it seems that her desire and enjoyment mattered to him only as a requirement he had to satisfy to get the pleasure he sought. It was not, in itself, important to him.

Neither of them was a monster, but they both have things to learn. I hope Grace learns how to recognize and express her wants. I hope Aziz learns to care about what his lovers feel.