In Fred Jordans case there is no distiction he was both, furthermore some of those traditional singers wrote their own material,[eg] bob roberts willie scott.
in a musical sense the distinction is not an important one, what is important is the musical interpretation and performance, the distiction is important for song collectors.
I think it is important to listen to traditional singers because it is the only way of getting access to the roots of the music, the musical performance//interpretation is not always better, although with those singers who seemed to be still singing regularly [harry cox] they are hard to better .