So, would you rather kill millions of Japanese civilians by normal bombs and gunfire, along with millions of Japanese soldiers along with 500000-1mill allied soldiers?
Because that was the option at the time, the Japanese would fight to the last man/woman/child. Not to mention all YOUR loved ones who would die in the attack on Japan.
So, given this choice, what would you choose? This was the reality of that time so don't try to talk your way out of it. These were the realities.
I always agree that one should take every measure to avoid civilian casualties and that was done by nuking.