As someone who's probably made one of the comments you're referring to, it's less "give Putin what he wants" and more "this war is unwinnable for Ukraine, it should cut its losses (territories that largely don't want to stay in Ukraine anyway) and negotiate."

Appeasement doesn't factor in because Russia has already won what it wants, and continuing a bloody stalemate will be worse for Ukraine than for Russia. Ukraine's position can only get weaker here.