Tom,
The trend towards shorter courses, which I embrace, is relatively new, and certainly not time tested. Even I admit I could be wrong on this one, LOL.
My stats have always been
1%-7000+
16% - 6800 or so
55% - 6300 or so
19% - sub 6000
8% - Sub 5000
So, a bit less than MK, but he probably knows what his courses do, I have to collect info from various courses and industry sources. I do believe the lowest 4 groups above are all trending to slightly shorter courses by preference.
I always remember my Dad walking out of a pro shop, after seeing the course was only 6,000 yards total. Now, I see seniors who won't play over 6,000 yards. It seems to be a somewhat generational change in male ego, from my limited experience.
What's funny is how many golfers still refuse to play a course without 7,000 yard back tees, even with no intent to ever play them. It is a residue of the old championship course mantra, and harder/longer is better as if a 6,600 yard course couldn't be well designed and fun.