I can see your point, murder is part of the job, but rape is not. Yet, I don't think such people even stop to think about it nor care. If they don't value people's lives, why would they care to value others' feelings?
I would be surprised if anyone who watched this series would have liked to go through what Pete has. I like Vegas, and Pete and I like them as a couple, but it doesn't mean I think their story was "lovely". In my opinion, as long as you acknowledge the problematic stuff, and like it just as fiction, I don't think it's wrong to like them. Yet, everyone has the right to their own opinion, and I can understand why some people hate their storyline, just as I can understand why some people love it. I guess that as long as you don't take it into real life and don't support actual real toxic relationships, let fantasy be fantasy.