Jim,
I don't think you're correct.
Mountain Lake, a wonderful Seth Raynor was one of the first housing development courses in America.
According to Mike Cirba, so was NGLA
Augusta was initially a planned community course.
Many great courses started as resort courses, then, as things began changing in America, people transitioned from going to resorts to building/buying their own homes in resort areas (sunshine/warm climate). Then courses like Pine Tree and others began their existance as part of a planned community. Those early courses tended to be good courses, but, with numbers comes a dilution in quality.
As the demand expanded and as the game became more popular, the golf course ceased being the lure.
The weather/area and the value of the home became the driving force for the general population.
So, perhaps, as the masses searched for a home in warm climates, quality suffered.
More recently, many, if not most desination courses seem to be of the highest quality since few, if any, would venture so far, to such remote locations, in pursuit of mediocrity.
But, if the masses came to those areas, I think you'd see a diminishment in the quality of the courses constructed.
As the numbers increase, quality almost always suffers.
That's my story and I'm sticking to it.