It's the money, stupid.
Seriously, Garrison Keillor has been a big disappointment to me. In the early eighties, I listened to Prarie Home Companion regularly, read his shorter fiction, and found him amusing in an undemanding sort of way. It wasn't until I read his first novel, Lake Wobegon, that I began to suspect that his "home-spun" quality masked a kind of contempt and nastiness that, I suppose, had gone right over my head. When in the latter eighties, he fell in love with his Danish sweetheart, quit the radio show and moved to Copenhagen to start his new life as a European, I had more or less quit listening. When he returned a couple of years later (because learning to speak Danish was so hard!)and started up his clone of Prarie Home Companion in New York, I couldn't be bothered.
Don't know what it is about a lot of modern humorists, but the older they get, the more bitter they get.
Not just the modern ones. Tom Lehrer was one of the most gifted, talented, and just plain funny musical satirists of the 60's. But he dropped out of sight in the late 60's, so thoroughly that many people had presumed he was dead. And although that link tries to downplay his reasons for leaving musical comedy, I once read a long interview with him in which he repeatedly expressed his political bitterness, with such comments as:
I'm not tempted to write a song about George W. Bush. I couldn't figure out what sort of song I would write. That's the problem: I don't want to satirise George Bush and his puppeteers, I want to vaporise themAnd:
They are calling it [the Columbia space shuttle tragedy] a disaster instead of a screw-up, which is all it was. They're calling these people heroes. The Columbia isn't a disaster. The disaster is that they're continuing this stupid program. [...] I was against the manned space program then and I'm even more against it now, that whole waste of money. And so, when seven people blow up or become confetti, then they've asked for it. They're volunteers, for one thing.Yeah, best that he not write or perform any more songs, if that's his attitude.