I doubt if TV is a suitable media for traditional music any more than it is a suitable outlet for classical music or jazz, neither of which get much exposure on TV. Hardly difficult to discern - it is a listening business rather than a visual one.

BBC Radio has loads of traditional music, little on national radio apart from Mike Harding but loads for example on BBC Scotland and N. Ireland.

As I remember it, Robin Hall and Jimmy MacGregor wrote a new song each night to comment on the news that day. Name one.

But I am not sure what this has to do with the collapse of folk clubs. Is the suggestion that once the BBC stopped showing folk music on TV then the folk clubs collapsed?

I doubt there is a correlation any more than there was a correlation between what the BBC/ITV showed and the rise of folk clubs.