Oh look, yet another usage of "needs to grow up" as a dogwhistle for "needs to adopt Puritanical values."
Newsflash: symbolic rejections of moral conduct are a method of cathartic stress-relief, not a declaration that said conduct is actually being rejected, and if you presume that's just an excuse to disguise actual lionization of immorality, you're going to be wrong 99.99% of the time (and no, fear of that last 0.01% does not justify your actions).
You'd think people who love playing murderhobos would understand that better than most other people, but for some reason the opposite seems to be true.