The fact that you would even try to compare those two events is just laughable. The context, world situation, available options, and quite literally every other conceivable variable was different. You could not get more apples to oranges. It was also 80 years ago, shocker, society has progressed and standards have changed. But anyways, the US options at the end of WW2 were these 3:
Option 1 was suicide. The Japanese fighters repeatedly demonstrated their willingness to fight to the death. The civilian population would have become involved and it would have turned into a long and brutal affair. The landing would've been bigger than D-day and no one even knew if it could be done. Japan would have been razed to the ground entirely if the operation had succeeded, as they WOULD have fought in every town, every city, and we WOULD have used conventional bombs to level everything in the way of the advance. That is how war was fought in 1940. Millions would have died.
Option 2 is what happened
Option 3 is moronic and self defeating. Japan would have rebuilt and attacked again, and no one in the 1940's would have even considered this as an option.
The choice was between a ground invasion that would have been a many years long brutal affair that would have inevitably involved massive conventional bombing raids on every major Japanese city, and destroying 2 cities. The generals at the time chose to destroy 2 cities. It would've been great if Japan just surrendered after they lost the Naval war, but they didn't, and never would have.