Which all sounds remarkably like the critique of techno contra by a traditionalist...except that Mr. Wilson-Jones is referring to people going more toward Henry Purcell (late 17th century musician), rather than strict Playford (mid-17th century).
My immediate response to this is hearty disagreement that tradition need be so rigid (shocker coming from me, I'm sure).
But beyond my knee-jerk reaction, I wonder: were there no regional variants, ever, that just didn't get passed down? Chaucer's version of English only got to be the "main" one we study among several dialects of the period because of Canterbury Tales, not because it was The Only Way They Did Things. (Ditto Beowulf, if I'm remembering right.) I would find it quite difficult to believe that Playford was the only one doing dances at that point in time; I'd believe he was the source of older dances Cecil Sharp managed to compile, but I somehow doubt he's the only one out there, and so I admit that I find the "Playford or bust" attitude a little baffling.
Likewise, what got passed down in American contra was a set of New England traditional jigs and reels (and other tunes dubbed "acceptable" by the traditionalists). How can we be sure that that's all they danced contras to? You mean to tell me that there wasn't anyone experimenting back then (even if not to the same extent as now)? I somehow find that hard to believe.
I keep coming back again to the XKCD comic I linked to about a year ago where Randall Munroe proclaims, "400 years from now, all the English of the past 400 years will sound equally old-timey and interchangeable." Perhaps at some point the idea that popular tunes of the day (be they "Cluck Old Hen," "Sandy Boys," or "Rolling in the Deep") won't be so shocking.