Myself, I thought O Brother was great fun as a film, and pretty good music too. If we're hung on on labels, as we regularly seem to be, it's folk-based rather than folk. So is the original music which is recreated in the film. And that's not any kind of put-down.

I'd definitely disagree on calling it wet. Mind you, since Thatcher's lot hijacked the term to mean anyone who wasn't a vicious sharp-toothed predatory sociopath that terms been a tricky one to use. It always was a bit susopect, with it's roots in prep schools playgrounds. (Which I believe is another expression that means something different in America.)

In short I'd see some of the comments on this as a clear case of "the best is enemy of the good."