https://www.history.com/news/why-the-real-life-hawkeye-pierce-hated-mash

Hornberger barely profited from the show—he only got $500 per episode, and sold the rights to the franchise for pennies. But his bitterness was more than financial. As the show’s reputation for its commentary on war grew, he distanced himself more and more from the series, and the character he modeled on his own wartime heroism and humor.

To add to this thread.....

My understanding was that the real Hawkeye was a conservative and pro-military, and hated Alda for what he did to the show simply because of that.

Makes me wonder how many military people actually hated MASH because they are conservative and pro-military. For me, the Korean War was an awful event, but the USA saved half of Korea from the horrid Kim regime and would have liberated the whole peninsula of it weren't for the Chinese. Now, should the USA have stepped up to save Korea from the Communists? An easy yes, until you realize that around 50,000 American troops were killed and many thousands of not a million Koreans dead.

Has anyone ever asked Alda himself his opinion of the Korean War?

516 Canadian troops died out of 20,000. It was briefly mentioned in an episode of M*A*S*H*.