Thomas,
Well, the USGA does have a prescribed method of measuring, and its from center of each tee to center of green, or as close as you can approximate given the free form of each. The hardest part, I think, is doglegs. I think they say to measure out to the center of the fairway where it bends, then to the green from there. However, on many old courses where the dogleg is at 200 yards and many players play well past it, it would be hard to pick a point. Most architects use something like 850 feet off the center of the back tee for the "turn point" when developing scorecards, but the final measurements are always different.
And, in some cases, the course will measure at least the back tees 6 foot off the back edge, if it gets them over whatever hundred yard marker they can exceed, so again, some folks in the biz still think it matters. And some measure all tees from near the back to stretch it out, on the theory that golfers love beating their score on a challenge, i.e., they feel good shooting a low number on a long course, believing they really played well that day, when in reality, they are playing much shorter than the advertised yardage. But, we digress.
The thing about distance is I see golfers gravitating to what they feel comfortable playing, like Peter. I like distances where I hit a few long irons, mostly mid irons and some short ones. I would feel its too easy on a short course where I was hitting all short irons. I think the general rule is a 5 iron is 2/3 your tee shot length, so a course should be say, 18 tee shots at 240 and 18 approaches at 160, average 36 shots, or about 6480 yards. And, I do see players gravitate to those distances more and more.
And, I see some evidence of developers wanting to take out back tees in favor of other community uses, like dog parks, veggie gardens, tot lots, etc. However, that is far from universal, and varies the question somewhat from what do golfers like to what sells houses in a community.
Thanks again for view points.