Everything is permitted. Just don't enjoy yourself.

Hitman movies are a whole genre. They are to nerd love stories what cowboy movies once were to screwball comedies. There are subgenres, too. Hitman farce. Hitman romance. I certainly don't want to come across as weak and girlish, but killing people for money is bad, right? Starting a story off with the presupposition that the protagonist is morally compromised beyond all hope of redemption can only be appropriate for an audience that feels itself equally corrupt. Nobody would accept this if the heroes were rapists. The difference? Professionalism. This is America. Anything's okay if you do it for money.