I think tacpot has got it about right. A non profit making Club, who has a clubhouse etc needs to cover those costs. I think if the organisation is profit making then it is not really a club.
The Club I am involved in, used to have a joining fee and a minimum flight time requirements and we got rid of those some years ago and it has turned out to be to the benefit of the Club, so I have doubts about joining fees as being a fair charge.
Membership Fees are a fair way of distributing those fixed costs involved in providing facilities. If we didn't charge in this way, the flying rate would have to go up and we all know how people feel about that!