The "ground invasion/famine due to blockade" are hypotheticals. They don't have the same weight as 2 real atomic bombs that killed real people. Evidence of plans for those could have been easily fabricated. Even if the plans were real, they could have been cancelled, or not worked.

I do agree that this costed less American lives than other options, and that in war most options are shitty. Inevitably, most involve civilian deaths. But the guy who picks the "let's mass kill civilians" is not going to get sympathy from me.

So no, I don't accept the "more people would have died" argument. Less US soldiers, yes. And it's not like the other side wasn't committing war crimes anyway.