People still vote with their feet, though, and for 95% of the facilities that I've seen with 36 holes or more, the easier course gets the most play.
Well, that depends on a lot of other design qualities besides just "difficulty," wouldn't you say? There's a local complex here in Denver where the easy course is also bland and monotonous. The harder course is has a totally different feel, and every golfer I know, from the relative experts to the lamest hacker would rather take a trip on the harder course, just because of its interest, its visual qualities, and its "fun factor." At the same time, from the right set of tees, that harder course is to my mind not all that hard (I have achieved my personal best score at that course).
For Mr. Mucci, making a course easier "connotes dumbing down the architectural features, or at least altering them toward mediocrity." But don't US Open setups make a course harder while at the same time dumbing down the architectural elements to the point of taking many of them out of play entirely?