I dig Terry Teachout, but I disagree with him. Carson was a master of comic timing -- the old-school comic timing. Jay Leno has comic timing that seems like a copy of a copy of a copy . . . you get the picture. It's canned. I suppose you could accuse Carson of being canned, but he put it in the can, of course; it was his product. (That's not meant to excuse him. He phoned it in a lot of the time, and over a three decade ride, I suppose that's bound to happen.) Carson's humor defined what was American television humor; it was quintessentially American, with its puns and gags, but with a viper's tongue for self-obsessed celebrities and preening politicians. Thus, if Johnny Carson leaves a vaporous legacy, why do Dave and Jay still do his show every night? True, Letterman added a (welcome) surreal bite to Carson's canny staging, but he didn't ever drop the canny staging, the knowing smirk, the mock-appeal to the audience following a joke that hits only the groan spot. And Leno has taken the Carson schtick and given it a good bleaching, so that what remains of the Tonight Show is no longer the meant and potatoes of Johnny's thiry years (and, yes, some find meat and potatoes boring) but a sort of predigested slurry, now with 50% more "laffs"!
Here's Johnny's legacy: He built a nascent format into an institution; neither of his predecessors, Jack Parr or Steve Allen, could have done so. For thirty years, Carson was the water cooler man; before Seinfeld and his catchphrases became Xeroxed break-room fodder (lifeless drones repeating "yadda yadda yadda" and "master of my domain" over and over, usually out of context), you came to work with a load of zingers to tell the guy who hadn't watched Johnny the night before.
The format is moribund. But that's not Johnny's fault, or not entirely. True, he didn't take chances; he wasn't edgy. But that wasn't his slot. He was for mass consumption. Is that the problem? Critics are quick to say that broad appeal means bland appeal -- but sometimes it doesn't.
Anyhoo, it's the curse of Carson's long, quiet retirement. The reexamination of his went on while he played tennis in Beverly Hills, and the new judgement is ready immediately, upon his death. Of the icon, the legend in his own time, the most successful entertainer, both in finances and ratings, of his active period, we can now only muster a dismissive "Carson? Meh."