It was not a good thing. It was a less bad thing. In war, nothing is good, but "bad" is better than "worse," and 150,000 dead in two Japanese cities was better than 1,000,000 minimum dead in a full-scale invasion of the main islands.
And something Mr. Carlson isn't considering, which is that by the time of the atomic bombings there were very few cities in Japan left to bomb outside of the northern area that could not be reached by our bombers. A few months earlier, Tokyo was firebombed and twice as many people were burned to death as were killed by either atomic bomb--the only difference between dropping an atomic bomb in Hiroshima and firebombs in Tokyo is that it takes more planes to carry all the firebombs, but to the victims the burns are just as painful and the deaths are just as dead.
You win the thread! Excellent argument