I stumbled on an interesting quote by Bobby Fischer the chess player on why he believes Mature really stopped acting:

"This is a common trick of the Jews, to blacklist their enemies and then to pretend they haven't. Now, I'll just give you a recent example that came to my mind. If you remember the great movie actor Victor Mature, he died a few months ago, remember him? Very handsome actor, he was in Samson and Delilah movies, and a lot of other movies, remember him? He oozed sex appeal out of all his pores, that sweaty look. Very handsome guy, I dont think he was a Jew. Anyway, he died a few month ago, and every singler report that I heard on the BBC, that I read in the paper, all were saying the same thing: That after I think it was the late 60's, early 70's, he retired from acting and he just went down to the San Diego area to play golf and to watch over his investments. So, they all made it sound like he voluntarily retired from being an actor for like the last 20-25 years of his life. But I remember an article, I believe it was in the National Enquirer or one of those type newspapers where he blasted Hollywood, he said 'They blackballed me out of Hollywood, they won't give my any more roles.', and so on. He was furious. So, this is the Jewish way. They blacklist you out of chess, out of acting, out of whatever your chosen profession is, and then they say: 'Oh, it's a pity Victor Mature didn't want to act anymore', or 'Bobby Fischer didn't want to play chess anymore, it's a shame.' This is their style. Now, I've got a long memory. If anybody out there doesn't believe me, do a little research. Check out, on Mr Mature. I remember this specifically. I remember it very clearly, he gave an interview, he was already down there in the San Diego area. Just absolutely blasted Hollywood. So, this is their technique."