I think it was the correct decision.
First, because the Japanese people are from a culture that values honor a lot. They still have samurai blood in their veins. They wouldn't surrender easily, and a land invasion would probably cost many more lives (for both sides).
Second, because the main priority States should have in a war is the safety of their nationals.
A man builds. A parasite asks 'Where is my share?'
A man creates. A parasite says, 'What will the neighbors think?'
A man invents. A parasite says, 'Watch out, or you might tread on the toes of God... '
No, at best it was a reason - not a particularly good one, IMO - and at worst a lie employed for propaganda purposes.
Every estimate I've seen, not just from government sources, places the death toll far higher without the bombing.
The main issue with the bombs is A) the vast majority of the victims were civilians and, if you rectify that issue, B) the morality of dropping the second bomb on Nagasaki and whether that was strictly necessary.
I'm basically with the people saying fewer deaths = better outcome.