Club membership might be aging for certain clubs, but I think there's growth overall - it's easier and cheaper to get gear and get help online. You probably don't need as much club assistance you might have in the past.
I think it's probably because more people are doing imaging vs visual (or both) too. If you're doing imaging, you're mostly likely doing gotos, plate solving, etc - you don't need to learn the sky as much (positioning/mapping). That learning process in the past would probably have been easier with mentors, etc helping.
Also, "we" as a society have become more anti-social buggers in RL, so being with other people in a club is "ugh".
