Rhe everyone complaining about various MC's bit taking lives, that just means they arenot psychos.
There have been studies, and even in war trained soldiers will often not shoot to kill at first. If you live in a civilized society, that is not horribly crime ridden, then the natural way to develop is to be averse to killing another person. No amount of arm chair quarterbacking and bloodlust from edgelords who will curl up in a ball the first time they run into a legitimate threat will change that