They've been dead for a long time.
Allen, Paar, Carson... to think there were three darn-near-perfect late-night hosts in a row, for almost 40 years... how did America get that lucky? And those guys came not long after Bob Hope had a decade-long run on radio with a similar format. At least the ones afterward, early Letterman, and eventually late-era Leno, had moments.
The current crop can't hold a candle. I'll be honest, I think it started with Conan. I know Letterman did a lot of bizarre, off-the-wall stuff, but Conan came from Harvard, and his entire shtick was steeped in smugness, a mockery of the whole format that stretched itself trying to be crass.
But you look at today's crop. Fallon is just plain bland, who makes up for a total lack of comic delivery with celebrity gimmicks. Colbert is a decent interviewer but his comedy drifts off into the inexplicable a lot, much like late-era Letterman. Corden ran so far over budget with his own celebrity gimmicks that he just lost his show. Meyers probably has the best delivery of the lot but he has a habit of getting smug. And Kimmel? I don't even know how to describe Kimmel. I mean, a guy whose signature bit is having parents lie to their kids to make them cry... there's no description for that.
You compare the structured bits that Fallon and Corden have done... but then you look at how Allen, Paar, and Carson handled celebrities. They had a roster of D-listers, famous outside the show but only marginally so, who were allowed to be themselves. Instead of being forced to mimic a music video, sing karaoke in a car or play classroom instruments, Carson just put Buddy Hackett or Charles Nelson Reilly into the guest's chair and let 'em rip. But that might also be part of the problem: today's guests have less to add to the conversation.
