Ah puzzled, although I, like most of us am a graet fan of Pete Seeger, I think he missed the point in that quote. No one I think, would suggest that the set "folk" and the set "good songs" are coincident. We all I am sure enjoy "good" songs whatever their origin or classification; but we will disagree, and argue about which songs are "good", just as frequently and vehemently as to which are "folk".
The argument about whether a song is "folk" or not may seem sterile to some, but then so would a debate about the classification of snails, rhododendrons, or tufted ducks; but people are still prepared to devote their life's work to these issues.
I think you would agree that we discuss a very catholic choice in music, but this is after all a folk and blues site, you would not expect to go to a site devoted to cannonballs and be able to discuss APFSDS and HESH rounds just because they are both fired from a gun, so I'm afraid the only answer may be to start your own site. You may of course find that it is the subject matter here which attracts the type of converation you enjoy, still it might be worth a go.
In the meanwhile I'm sure we won't mind the odd side track, -just don't mention Niel Diamond