Simpson in general was all over the place for me. He started off as just another sympathetic victim and a good guy cop trying to do the right thing... but he went off the rails almost at random, and him going around blasting up his fellow police officers for doing their jobs and trying to murder the woman that saved his life felt like a "kick the dog" moment for him that was inconsistent with the person we met at the start of the series.
... And then, of course, Jessica just proves his point and decides to kill Kilgrave instead of capturing him, which was what he was advocating practically from the start. It was a poor character arc for both of them, in my opinion,