Let's distinguish between two kinds of "purists." The first kind is made up of mostly amiable experts who know what actual traditional music or sounded like, but who can evaluate a contemporary performance on its own merits.

"Snobs," on the other hand, often don't know half as much as they think, and seem determined to make everyone else know it. They tell others that if they don't perform up to folk-snob standards, they're corrupters of art.

Both groups were probably more numerous in the early '60s, but neither has ever been common, because most people just don't set themselves up as outspoken taste-makers and theoreticians.

Of course, anybody who dislikes any aspect of a performance simply for not being "traditional" enough may be derided as a purist.