Ted,
It's been my limited experience that some courses are labeled as overrated or underrated due to geography or regionalism.
It's an example of the big fish in the small pond, or, living under a giant shadow.
The rating process tends to be regionally oriented.
Raters from Florida aren't providing the preponderance of data for golf courses in Oregon, Kentucky or New Mexico, and vice versa. And as such, regional assessment seems to prevail.
If Mountain Ridge was in the Mid-West, South West or West, there's no doubt in my mind that it would be deemed top 100.
Mainly because it would stand head and shoulders above its local peers.
However, in the Metropolitan NY area, it's one of many great courses and as such lives in the shadows of the Winged Foot's, Pine Valley's, Shinnecock's, NGLA's, GCGC's, Baltusrol's, Ridgewood's, Quaker Ridge's, etc., etc..
Pumpkin Ridge seems to exemplify the concept.
In that area of the country it stands out.
In the greater Metropolitan NY area, or the greater Philadelphia area, it would be, "just another golf course", and certainly not a top 100 golf course.