I think the main problem would be that many of the famous or fairly famous nowadays don't play - and in some cases have probably never played the folk clubs; they inhabit a world of concert halls, festivals, foreign tours and recording studios. Time was, you served your time in the clubs. Festivals were few and far between and hardly any of us had the chance to record our stuff. It was the same in the pop world; people like the Beatles had played local 'beat clubs' here and in Germany for years before getting a recording contract and becoming more widely known. The career path for young folk musicians now deems to be: Folk Degree Course - Young Folk Awards - instant career in fesstivals concerts and recording. They don't owe anything to the clubs. The great irony is that the whole 'Folk Industry' (see another current thread!) owes its entire existence to the clubs. Much the same in the pop world, where you owe your (probably brief) career to the likes of Simon Cowell deciding they can sell you for a few months.
It'll be interesting to see what sort of response - if any- you get from the glitterati. (It would also be interesting to know who had responded, but I can understand your reluctance to name names).   
The Famous (and sarcastic) John Kelly.