I've never liked the man and the peice that Clyde posted didn't help.
Yes, the UUA does sometimes claim some people as UUs who weren't really. Even religious liberals are not immune to overzealous PR.* We shouldn't do that. No argument there.
But as an excuse to make fun of UUs for decades, that's pretty thin.
If he can make fun of UUs forever solely for that reason, surely I can dislike him forever because of the time he found out somebody was making "Prarie Ho Companion" t-shirts and sued the t-shirt maker. (This is particularly annoying given that parody is quite clearly fair use, so the lawsuit was likely designed to scare and/or bankrupt the people making the shirts rather than actually have justice done. My understanding is that the law is totally against Keillor. The only way that would not be the case would be if people didn't understand that "Prairie Ho Companion" was not a product of Garrison Keillor's media empire, a point that was made clear on the page where the shirts were sold.)
More of my commentary on that here.
*Though not as overzealous as an old friend's grandmother who was convinced that John-the-Baptist was a southern Baptist like herself. If you think I'm making that up, you've never met a South Carolina grandmother.