The reality of "The Vacant Chair" done Bluegrass is a bit disconcerting, too. I forget who I heard do it.

(actually, this doesn't speak directly to the issue of the thread, as 'style' and 'taste' can be debated separately.)

What would be a more likely problem is someone interrupting a discussion of "Sweet Betsy from Pike" and arguing that it is 'not really American', as it steals the tune from "Vilikens and his Dinah"...something like that. A huge amount of N. American music does have roots in the UK and Europe, so decisions would have to be made.