The Bomb probably saved a million lives that would have been lost during the invasion of Japan. And countless more that might have been lost in conventional battles that never happened during the nuclear stalemate of the Cold War. If you're going to rate these guys on such extraneous grounds, you gotta give the contest to Einstein.
Einstein did not invent the A-bomb. He did devise Relativity, which is even more illusory than Newtonian mechanics.