"Asgore would be killed on sight": Asgore is the most powerful boss monster. it's also stated by Toriel that he could have done it peacefully (getting souls from deceased/dying humans, or even borrowing them, as it's shown that SOULs can be returned to their owners.)
okay a lot of repeated things i keep seeing that don't really make sense with the context of the games:
"Asriel already tried it": Asriel was literally carrying a corpse, and the humans mistook Asriel as the aggressor.
"It would've started another war": maybe if it was done immediately, HOWEVER: by the time Frisk falls into the underground, the human's knowledge of the existence of monsters is only through old legends, and it's been a VERY long time since the war happened.
