In those endless 'what is folk?' threads we've surely established that any kind of song can be 'traditional', at least in theory.

Indeed, just as all of them can be said be traditional, if not directly in an of themselves (though I might argue otherwise) then as products of any given music Idiom with is Traditional by default, just as people write new songs in Idioms old & new today, and new session tunes, or the Tradition of Northumbrian Pipe Music in wich composition played a huge part and continues to do so today.

How does that affect the argument?

Less of an argument - more of a celebration. People are more important than the music they play. One wonders how much of The Tradition was shaped by the selective agendas of the revivalists - one does, after all, hear such tales...

Enough. I'm verging on heresy here which is never a good thing on open forum.