It is a bit chicken and egg. 'Flying clubs' are actually training companies. their activites are thus based around attracting people to learn to fly and once they can no longer sell them anymore training persuading them to stop drinking the coffee and clear off.
Changing that model would require enthusiasm, effort and good management - in short supply across most of industry and almost unheard of in GA.
I am presently a memeber of a real flying club, but they do not have access to aircraft of their own. So there are talks, socials, flyout and fly-ins and a fair bit of trying to put things together.
But at the two 'clubs' where I trained they had touring aircraft which were under utilised, the 'clubs' used they for IMCs but had a complete aversion to taking them away....
So the majority of clubs do not encourage PPLs to stay and then there is the shear weight of restrictions, criteria and just general aggravation that is necessary to maintain a licence courtesy of JAR and now EASA. No wonder people just fade away.