Why did the actor who played Frank Burns leave?
Typed the question into Google, here’s your answer:
He (Larry Linville) was offered a renewal for two more seasons when his contract expired, but he declined. After five seasons, Linville had grown tired of playing the character. Linville felt that he had taken the Frank Burns character as far as he could, and chose to leave the series to pursue other roles.
According to the M*A*S*H season 6, episode 1 “Fade In, Fade Out” IMDB page, “he felt that the character of Frank Burns was too one-dimensional, and that they’d done all they could with it”.
I believe Linville and Stevenson both left over money issues. Gary Burghoff (Radar) also left the show only to find out there wasn’t much demand for mean-spirited dwarfs.
Afraid of being typecast, which (unfortunately), he was. Larry Linville spent much of his remaining career as a stage actor in Canada. Also, there was only so much you could do with a character like Frank Burns, and I believe Linville saw his part growing smaller on the show.
One more anecdote—which will come as a surprise to no one. I remember reading Jackie Cooper’s autobiography a few years ago. Cooper spent his entire life in Hollywood and had a lot of success, as a child actor, a studio exec and as a director. He directed a number of episodes of M*A*S*H until he started butting heads with Alan Alda, who had become the insufferable star of the show and enjoyed throwing his weight around.
Alda made sure Cooper didn’t get any more directing assignments on the show. Other people left the show during the same period, including Linville. He always said he wanted to do other things and didn’t want to be known only as Frank Burns. But it’s also clear that M*A*S*H became “The Alan Alda Show” at a certain point. As long as other members of the company accepted that, they were fine. Those who had a problem with it usually moved on.