I would never disagree with so eminent a scholar as Dick Greenhaus, but his fun for the doer but not for the listener argument is, both, cogent and inaccurate. It is, surely, fun to do, as all the present and former Barbershoppers have attested. It is, also, a popular genre as performance art. I have attended more than a few Mainliners concerts, and there wasn't an empty seat in the house. They perform at a number of summertime venues and they are the most attended shows of the series. I will, personally, escort Dick and Susan to a show so he can count the house for himself.
Technique is a big part of a SPBQHSA performance and, to this end, they rehearse a lot. So does every other singing group, or they should. Performance is not the same as singin' and strummin' on one's front porch. It is not a jam session in festival parking lot. As I, previously, stated, One could make a decent argument that folk music cannot cooincide with professional performance. But some traditional music has always been performed and was so intended. Child ballads were the creation of long gone singer/songwriters who made their living singing them.
My original post was questioning why some traditions are more folkie than others on Mudcat. It doesn't take a genius to list the OK and the Ignored. On the A List, is Ballads, Blues, Bluegrass, a biss'l Klezmer, Irish and every singer/songwriter with a CD. On the D List,
we find Jazz, Polkas, Barbershop, Cowboy Swing, Italian and every singer/songwriter who is successful (except Dylan, maybe).
Did I miss anyone?

                      Mike