I think people just generally have a lot less sympathy for literal Nazis, who the Germans voted into power, and any aggressors in a military campaign. America didn't just nuke Japan out of nowhere, the Japanese opened the door to that when they bombed pearl harbor and attempted to conquer the Pacific.
When the bad guys get what's coming to them, people don't feel so bad about it. And don't pretend civilians are completely innocent in these cases. You blame Americans for voting Trump into power, right? Then you also have to blame Germans for putting Hitler into power, and the Japanese for supporting their leaders' violent colonialism. The conflict was hugely popular on the home front in Japan. Until they started losing, of course.
Japan and Germany were not the victims of WWII.