I don't disagree with any of your comments Les.
All I would say is that I do know of some rather introspective folk clubs which do little to attract new visitors. To a newcomer they could appear unwelcoming. I also know several which go to great lengths to make newcomers welcome.
The internet is a cheap and easy way for folk clubs to present themselves to a wider audience and I know that Les uses it expertly to publicise the ventures he's involved in. In contrast there is a 'club' local to me whose internet presence amounts to one page which is about ten years out of date (I kid you not). There's another which books big names which is full of erroneous links to previous year's guests. Using it has an Alice in Wonderland feel - and they have the audacity to suggest that their site is the only one that can be trusted to be accurate.
If clubs take the trouble to put themselves out there on the net in some way or other (and at least take the trouble to ensure that information is up-to-date and accurate) it does suggest that they care and would be welcoming and maybe the reverse is true.
While I'm on a roll, not knowing where this is going, I'm going to suggest that FaceBook (which is used increasingly by clubs and folkies for promotion and communication) is a little inward looking in the sense that it excludes a whole raft of people who don't belong to FaceBook. It's a great aid to communication for those who are members of FaceBook sites and very easy to use but it does IMNSHO have some limitations.
Yes, 'famous folkies' should give a shout to Folk Clubs but then it behoves the audience member who has been persuaded to do a bit of research or they may be disappointed.