There's a special kind of person that does not realize that the best way to end a war, better even than completely killing your enemy, is getting the civilians to support them to stop supporting the war effort. If the people are more afraid of you than they are of their own government, suddenly reinforcements stop getting trained. Weapons stop getting manufactured. Production ends and in the worst cases coups happen.
There's a reason we fire bombed Tokyo. Its the same logic behind the less effective atomic bombs. It wasn't about the death toll necessarily, it was about sending a message.
Japan sent the Chinese people a very strongly worded message, so much so that 80 years later, they still haven't forgotten it.