Steve, I apologise in that case. I had no idea you had not seen the show (it's not clear from any of your previous posts) and the impression I had was that overall you had the opinions I've reacted to, apart from a few minor saving graces you mentioned in the other thread.
As I have no idea which acts and shows you are in fact referring to, I can't really contribute, except to say that at today, as always, marketing/management craft is as important as playing, singing, writing/researching/arranging and performing craft. Put simplistically, you add the scores together in each category and the higher the number the larger your audience will tend to be. 'Cross-over' acts have always had good management, from The Wurzels to Richard Thompson - it's a requirement, because you're now competing with non-folk artists. It does mean some compromise, and it does mean that soft-core talent will tend to triumph over hard-core (though not always - depending on the strategy etc).
If you get do hyped beyond your capabilities, or to the wrong market, then you don't tend to stay there for long. The market decides.
All the mainstream outlets, as identified by Ralph, are themselves in competition for their slots. They have to make the maths add up - audience figures, budgets, tick-boxes etc. They are competing with other types of TV or radio programme, so they have to balance what they do carefully to maximise their chances of getting the next commission. The Peter Principle again.
You can no more ring-fence folk music in marketing/business terms than you can in terms of repertoire or performance style. Even two-bit travelling van-singers like me put as much time and effort into desk work as writing, practising and performing. The higher up the food chain, the bigger the audience, the bigger the risks and the fiercer the competition - so the more power you need in the back office.
It's just how life is in a neo-liberal economy.