I, for one, wish that there were any sign of sailing declining in popularity. All that I can see is that hardly anyone sails dinghies any more and that 32ft is considered 'entry level' for a cruising boat, which means that anchorages are become increasingly over crowded with vast 'condo-marans' and huge monohulls - where there are no marinas to soak them up. This certainly applies to ocean voyaging and there seems to be no shortage, as David says, of boats out on the water. Maybe fewer people are actively sailing on a regular basis, but the boat numbers would appear to be on the increase.
As to clubs: this is an international problem across all areas. When I was tramping in South Island, all the clubs I had anything to do with were concerned about the difficulty of attracting new members. Without the clubs to maintain them, we will lose our wonderful network of tramping huts, just as boaties will end up having to pay for everything to a profit-oriented business, if they don't join the local boat clubs. However, as boating increasingly becomes the rich man's sport that it was always (erroneously) perceived to be, I don't suppose most boat owners care.
Junk rig, on the other hand, seems to attract the sort of people who realise that what goes around comes around and that you have to make time in your life to help your community so that your community will give back to you. It's called enlightened self-interest and is the explanation for why all these different clubs used to flourish. Alas, the 'enlightened' bit seems to be becoming more and more rare, so people join the club for what they can get rather than thinking (excuse me JFK) that it's about 'What I can do for my Club, not for what my Club can do for me.'
Maybe we'll find junkies taking over the boating clubs!