I put Johnny Carson in there to see if you would really read the list !<quoted text>
While I could take issue with some of the names you listed (Raymond Burr wasn't really out during his lifetime, Richard Chamberlain didn't come out until his career was almost over, and I've never heard a word about Johnny Carson being anything but straight), I understand ... and basically agree with ... your point.
Good examples you left out are Sir Ian McKellan, Elton John, Patsy Kelly (the 1930's comedian who NEVER pretended to be anything but 100% lesbian and was still making films decades later), Chad Allen, Cheyenne Jackson, Jane Lynch ... as you said, the list goes on and on.
The point is that even if they were not out to the public at large, it was an inside secret that these actors and performers were gay, and it didn't hurt heir careers.
And for those I mentioned that are thankfully still here to enrich our lives with their gifts and talents, it hasn't hurt their careers either.