One of the reasons I love Japan: The sense of duty in the average Japanese citizen is over the top, and I really like that (and wish more Americans were like that).
However, I think that fact was also a factor in the decision to drop the bomb.
When the US was taking back the Aleutian Islands, rather than surrender anyone, the Japanese went through their field hospital and slaughtered all the patients...if they didn't commit suicide, the doctors used grenades to kill them. One of the doctors who participated in this kept a diary, and his diary was raced back to D.C. to make them aware of what we faced...the fervor of the enemy.
Emperor Hirohito ordered his civilians to commit suicide rather than fall under the control of the Americans. In Saipan, many Japanese citizens complied, with families running off of what is now called "Suicide Cliff" rather than become subject to US Marine control.
Kamikazes...enough said.
We had destroyed their entire navy...literally, they had few ships left. They sacrificed their last ships in a suicide attack. And yet, they would not surrender.
This was an enemy unlike all other enemies of the US.
We can argue whether the bomb should have been dropped from a moral perspective. But, I can certainly see why the decision was made, given the mass suicides and civilian fighting the US expected to see if we invaded the main islands of Japan.