Okay, I should probably explain why I'm so anally rampaged because I severely doubt the guy who wrote this really knew what he was doing (and of course his spergey fans wouldn't see the problems here).
Spoilers ahoy
Here's the status of everyone after the True Pacifist ending of Undertale:
Asriel: A soulless, possessed flower at the bottom of a pit, perpetually looking to satisfy his eternal hunger for violence.
Toriel and Asgore: Still childless and presumably immortal without their actual son. Oh and they're still divorced because pseudorealism.
Frisk: Their substitute child. You can let Toriel be your mom and never tell her that her actual son is still a fucking soulless flower in the bottom of a cavern while she bakes you butterscotch and cinnamon pie. Seriously, you've replaced that kid. Nobody knows or cares who he is anymore. And you're supposed to be the good guy here?
Everyone else: Everything will totally be cool in this world full of potentially hostile humans, right? Eh, they knew what they were in for when they did it.
Now, granted, Asriel tells you to not tell them anything, the usual selfless "Remember me as I was, don't break their hearts" shit.
But you can't respond with "Yeah, no, fuck that bullshit. I just saved everyone's ass with the power of motherfucking friendship, so don't give me any shit about what I can and can't possibly do. I've got a damn near omniscient skeleton over here, your fucking parents, a researcher who's actually done work on this shit, and the ability to reverse time. You little bastard, I didn't play this fucking game for nine hours to leave your bleating ass behind after sparing all these worthless motherfuckers."
It'd be like if the Mane 6 in the second episode used the Friendship Cannon on Nightmare Moon and she went back to the moon forever. Luna? Who's that again? Fuck that cunt.
And the creator obviously doesn't see the problem here. None of the characters comment on this! You're the hero, nobody remembers Asriel, good job, you win. It's just so dissonant to reasonable human values that it represents either a serious logical disconnect, an absolute failure to parse player motivations (the whole "Chara" thing kind of supports that Toby doesn't quite understand psychology) or he just quit caring halfway through writing the script.
Either that or he's playing a long game and he'll give the fans DLC for Christmas to unfuck this mess and give players a satisfying battle to purge Chara entirely (you know, the bad guy we never actually get to put an end to?) and give the Dreemurrs their actual kid back. "Ha ha, you really thought I was going to end it like that? Lol jk here's the actual ending and pay me another ten bux for it because I'm a huge kike"
You just don't do this kind of crap in fiction like this unless there's something mentally wrong with you or you're intentionally trolling the shit out of everyone. You can't have Care Bears end like Game of fucking Thrones and not comment on it.