Dropping the bombs was necessary. Choosing civilian targets versus government or military ones is debatable.
the destruction of Japanese will was absolutely necessary
They were, as many cities were, of mixed use. I have read other stories that weather was part of what went into attacking those cities as opposed to other nearby cities.
And the Allies had leafleted the region not too many days before warning that the region was liable to bombing and that people should get out.
All in all, remarkably humane given the vengeance that Japan richly deserved.
When the factories are in the cities and the "civilians" staff the factories, there is no debate.
when the civillian targets have factories making military equipment, they are military targets.