"Removal" means to take away from one place and convey to another. What Sharp did (whatever over-pessimistic ideas he may have had about extinction) was to reproduce the form (or a tarted-up version of it) elsewhere. I don't see how that's stealing. If he'd nicked it, how come all those 'pure drop' singers like the Coppers, Pardon, Jordan, Blaxhall Ship, etc., carried on their singing traditions without any interference from him?

Attempts were made by at least some of the Edwardian collectors to record the subtleties of melodic variation and ornament that were essential to traditional performance style, and of course the more recent Revival, far from overlooking the craft of traditional performers, has celebrated it.