When it comes to forming my opinions....
I'll take thousands of data points of rounds of actual Pro golfers in peak form played on various courses and years of play....over a measly 2 data points.
It all depends. Which confirms your biases? 2 data points or a fuller set? Much of it depends on who chooses the data and the parameters, and that is before saying anything about the inferences which they then make from the selected data.
Shorter courses, less time to play, less acreage to maintain etc etc, fine by me. And even better if said courses are playing fiery and have difficult/evil green surrounds and putting surfaces.
Is expense the issue in the game's decline or is it the amount of time to play? Both?
As a real estate broker who has delved in land, I can tell you unequivocally that the price of a tract has much more to do with other factors than size. And depending on the configuration and characteristics of a tract, a 200 acre site might yield a sub-7000 yard course whereas a 175 acre piece could very well support one of 7200+ yards. Ceteris paribus (holding all other things equal) does not provide useful insights on this subject. Ditto for the operating costs which have more to do with location and objectives of the club.
As an occasional tournament official, it is my experience that the length of the course has much less to do with speed of play than the things Jeff talks about. In fact, the preference for F & F conditions and "evil" green complexes are prescriptions for extremely long rounds (and probably why many beginners walk away from the game- they can play shorter tees, but they can't avoid the conditions desired by those short, accurate drivers of the ball who possess great short games).