"Trad doesn't not equal good anymore than modern equals good."

Who said it did? And, by extension, I'd like to add that trad equals good no more than modern equals bad - there are some brilliant renditions of trad songs that blend contemporary, plugged-in instruments and ar5rangements with a respect for the material - well, god bless all who sail in her. The only thing that's sacrosanct as far as I'm concerned is the preservation of the body of material itself - but if people want to come along and interpret it in new and exciting ways, so much the better.

However, it might be true that at the other end of the spectrum, the tradition, because of its history and ethos, has a different set of value judgements applied to its interpretation and performance. As this music has come from ordinary people, it's still perfectly valid for ordinary people (with not-great voices and little showmanship) to perform those songs. Traddies get this - non-traddies often don't. Reactions can vary from impatience to rudeness. I think non-traddies often see these interpretations as somehow self-indulgent ("Did they have to sing EVERY single verse? It's not as if they could even sing very well!"). In fact, this collective ownership of the traditional musical canon is part of what keeps it a living tradition. There's a trend toward a less participative experience that you can see at some festivals, where people don't come to take part in any way, but imply sit back and let the professionals entertain them. I might struggle to come up with a definition for folk, but I'm pretty sure that's not it.