Why do some far-left liberals condemn the U.S. dropping two Atomic bombs on Japan in WW2?

People that condemn us for bombing Hiroshima and Nagasaki are a disgrace to the country. By dropping the A-bombs we saved countless more American and Japanese lives than we would have if we invaded Japan instead, many American's, Japanese others would not be alive today if we invaded instead of dropped the bombs. Japan started this fight by attacking Pearl Harbor, and by invading China and by annexing Korea. This is all Japan's stupid emperors fault, he could've surrendered when Truman warned them that we would bomb them unless they surrender, the Japanese refused to surrender. I don't apologize for it, we did what we had too, if anything they should apologize for the war crimes they committed against the Chinese, the Koreans and the U.S. and others.

It is furiously insulting to all the American and Japanese and Chinese and Korean and other lives that were saved to condemn the Atomic bombing of Japan and apologizing to them. Even many democrats supported it.