>>716169636
Anon, the point of Undertale is to explore the nature of the player's relationship with the games they play. Killing enemies isn't shamed because the game thinks killing is bad, it's because the game is checking you on whether you're the type who feels bad playing an "evil route" in a game. It directly calls this out at the end of Genocide; if you actually didn't enjoy what you were doing, why did you bother? It's not required progression, and if you think the characters are "real" enough that you feel bad about "hurting" them, you shouldn't be doing that, because games are meant to be fun.
It's Spec Ops The Line's whole shtick about "you could have stopped when you wanted" except Undertale actually DOES give you ways to stop and do something else. On the Pacifist Route, you use the fact that you're playing a game to break reality in a way that results in the happiest outcome for the characters you've grown attached to. On Genocide you don't (or shouldn't) give a shit, and are pushing things to see how far they'll go and how hard characters will fight back.
The only thing Undertale tries to make you feel genuinely bad about is if you do these things and then whinge about how it wasn't fun or how you didn't like the characters reacting appropriately to being slaughtered. If you didn't have fun doing it, why did you bother doing it? You're playing a game with multiple routes, you could have down something else instead of picking the path you don't enjoy.