I would have thought that being 'under-exposed' on the folk scene may be a maatter of chance really. In the past, some older 'traditional' musicians were delighted to be discovered and made a career out of their repertoire- Willy Scott and Fred Jordan spring to mind.

It's all changed now, but I know of many proficient singers & musicians with no interest in the perilous living offered by the folk scene & hence become 'under-exposed' by choice?