I like to look at these measures through my psuedo-economic lens as quality signals, stand ins for more refined, or in regards to GCA, more opaque quality measures.
The early century digital camera revolution presents a great example of this, as manufacturers battled on Megapixels, knowing full well that buyers often unable to discern other differences in the product, but could easily correlate more megapixels with higher perceived quality.
Consciously or not, the challenge you have to get players past golf's deeply ingrained quality signals for these changes in par to make a difference, and even then you are just shifting numbers from one quality signal, Par Tested, to another Par Defended.
The quality signals in golf as I see them are:
Number of hole: 18, not 9, 27 is weird, nothing else. Look at the big resorts. They build multiple 18's.
Par Tested: 72 is the sweet spot. When you stray high, the course is a ball buster. When you stray low, it's easy or it's cheating you by not being enough.
Par Defended: Not being a scratch golfer, am guessing here that scratch golfers expect to play scratch golf.
Rating and Slope: in the US this a proxy for Par Defended. I don't know that there is a number too high as far as acting as quality signals, but when the rating and slope are in the 60's and 110's, who doesn't think "cow pasture?"
Yardage: 7000 from the tips seems to be the gold standard.
Price: The universal quality signal.
Leatherstocking has been getting some love and as an old course might fit in to this category. How does it do on quality signals?
Holes: 18 Check
Par tested: 72 Check
Par Defended: I believe it was said State Ams break 70. No check.
Rating and Slope: 70.8/135. Mixed. Below Par rating, but healthy slope signals challlenge, commemsukrate with:
Yardage: 6416. No check.
Price: $99 weekend. In this area Check.
I think dropping Par Tested here would be a mistake. While a Par 70 that played above Par (70.
is good, sacrificing the quality signal Par Tested would be a bigger loss. The slope signals that despite the yardage the course is no pushover, and the price signals much the same, as if they can separate you from a C-note, their must be something going on those 6,400 yards.
Interstingly, the decision to change Par Tested for the Pros fits in with this viewpoint quite well. For the week of the tournament, the cost of lowering Par Tested is outweighed by the very visible benefit of increasing Relative Par Defended. A course the Pros play in -15 seems easier than a course they play in -7. Sure, looking objectively it's a shell game, shuffling some numbers around, but the effect is that by shuffling the numbers relative to anchoring quality signals, the intrepretation of a single outcome can be manipulated in mind of the observer.
In a world where consumers have limited time, information, and understanding, minding quality signals is important, and changing them in an adverse way should be undertaken with a clear head.