Isn't this a self selection bias? Of the older courses that still survive, the best ones are more likely to have survived than the crappy ones. Old money is more likely to be interested in a long established club, rather some place that just opened 10 years ago. So they are more likely to be joining a club that is architecturally of higher quality. With the new ones sometimes you get C&C or Doak, and sometimes you get a signature course in a housing development.
So here's the question, of the courses built in the last 25 years, which ones do you think are more likely to be around in the year 2100? Courses like Sand Hills and Pac Dunes, or signature courses built to sell a McMansion housing development?