If the supply of golf courses keeps on growing and the demand (number of regular golfers) doesn't, I would predict that in the near future competition will drive down greens fees. Although I often think about buying a retirement home in a golf community, I am very concerned that some of these places will find it hard to get and retain members, and that will put tremendous financial pressure on the existing homeowners/members.
It's been a booming real estate market for the last 10 years and many people probably think it won't end -- the same people who thought that about the stock market in March 2000.