I suppose it just comes down to the one standard that you included most prominently in your analysis of the course: resistance to par. There are some who think this is a highly overvalued criterion. Others prize it greatly. I find myself in the middle of these two extremes. I can get a little bored if a course is really easy and can get turned off if a course is just too damned hard. For the courses on the "easy" side of the ledger, architectural niceties like template interpretation can turn an easy round into a fun and intriguing round. I would guess that if you played and compared a number of Raynor courses that your second trip to Blue Mound might be more rewarding.
Terry - you hit the head on this one. It really depends on what you are looking for.
If you are a scratch player and are asking if it is a stern test of golf that punishes bad shots, Blue Mound is not your course. As with all Raynor courses, the greenside bunkers are the course's protection...and the greens are so large that the good player usually can navigate them.
On the other hand, Blue Mound is a course that is wonderfully designed and presented for its membership. As I played it, I found myself repeatedly saying that this would be a great course to be a member, as it is enjoyable (although not a stern test) for the lower handicapper, like myself, yet can be played by the higher handicapper and still thoroughly enjoyed. In fact, an older gentleman playing with us liked Blue Mound better than every course on our Wisconsin trip (Erin Hills and the Kohler courses).
I think it is deserving its ranking of 126 GW Classic (in fact, I think it is closer to top 100 Classic). While Mike Treitler mentions 6-9 (for good reason), 11-13 are equally as good. In fact, I think 13 may be the best Redan that I have played to date (which includes Pacific Dunes #17, Old Mac #12 and Camargo #15, among others). On the downside, I will agree that the starting 1st and 10th are a little boring and the driving range/practice area needs work.
95% of a golf club's membership are people that cannot break 80 and just want to enjoy their round, while still having interesting holes with fun shots (ie. like any putt on the great 2nd green or the long approach to the Punchbowl #8). Blue Mound meets this criteria very well. As I have said in the past, there is a place for penal, championship golf, but great member courses like Blue Mound should be more of the norm.