I happened upon an interesting 1991 tribute to Johnny Carson. A small part:
It's not all that fashionable to be a fan of Johnny Carson. No one likes him except most people.
I have heard not a few folks brag of not watching him . . . even a few dismiss what he does as easy. Yeah, right, that's why most TV shows last twenty-eight years. Though the man has enough money to buy Nebraska, his ties to his home state are clear enough that it is easy to dismiss him as a panderer to Middle America. "Middle America" is an oft-heard slam leveled at anything in entertainment that commits the backwater sin of not being overtly L.A. or N.Y.
I don't think that begins to explain Carson. He has developed, perhaps not even consciously, an unerring feel for what interests America, what they want to hear. He knows, for instance, that Big Stars whining about how tough it is to be in Make-up at six in the morn or what a pain it is to be pestered for autographs, send viewers fumbling for the remote. Which is why, as on few other chat shows, the host politely terminates such ramblings and segues to the next topic. He knows that America squirms to see folks on TV fawning over non-entities . . . so Johnny fawns rarely and, then, only over a Bob Hope or Jimmy Stewart. He knows what America knows about and doesn't. Other shows settle arguments about that using Carson as the windsock. I wrote a variety show once for which a sketch was proposed about ratings "Sweeps Week." A debate broke out as to whether that was too inside for the viewers and the discussion went round and round until someone — probably me — pointed up that Carson often does jokes that presume a knowledge of what "Sweeps Week" is. That settled it. Because, on things like that, Johnny is rarely wrong.