Has anyone given any thought to the possibility that the Folk Revival or Folk Scare may have been brought about by the commercialisation of the music, A sort of dumbing down or tarting up process which made folk derived material appeal to a wider audience?

Think back to The Weavers, The Kingston Trio, Lonnie Donegan for instance.

Some of that wider audience were interested enough to find out more about the origins of the material, liked what they found and stayed with it.
The interest in blues in the UK and probably elsewhere was boosted in a similar way by pop groups like Rolling Stones.

Even Jim Carrol I believe came in via an English folk group popular enough to have their own radio or tv (I can't remember which) series

I don't believe folk music will die but just continue to be a minority sport just like it was before pop charts came along.