I looked up some basic numbers on the death toll of World War II in the Pacific theater. It seems to be in the ballpark of 30 _million_ people that died.
I think it would be fair to say that bombing a civilian city into oblivion is immoral. Unfortunately, Hiroshima and Nagasaki were not the only cases where this happened. And at the end of the day, it's killing people that's immoral, and vaporizing them with different types of bombs... well, it feels like we're starting to split hairs here, right?
It's odd to me how bad we are at sensible discourse wherever the word "nuclear" is concerned.