Had there been a viable alternative, I might agree with you. There was not, so I don't.
There was actually two alternatives. The first was for the Japs to surrender when we warned them before dropping the first bomb that they we were about to hit them with a weapon of mass destruction. The second alternative was for the Japs to unconditionally surrender after we dropped the first bomb and warned them that we were about to drop a second if they did not surrender.