Rich, I don't know if I'd call it a PV Syndrome, though I understand why you use PV to illustrate the point.
My short answer to your original question -- "Has the concept of 'splendid isolation' been as good a one in terms of golf course architecture and golfing enjoyment as it has been a bad one for the trial lawyers association?" -- is, No. The costs outweigh the benefits, and arise more out of fear than from any hard probabilities and statistics.
Macdonald's bit about Westward Ho! always comes to mind when we talk about isolated holes and indemnity:
At St. Andrews there are only two holes that cross, the seventh and the eleventh. In view of the lamentations that one hears at the nineteenth hole regarding the danger of being killed by a golf-ball where two fairways cross, these timid golfers should have played at Westward Ho! with its twelve crossings. To this day, St. Andrews men like to tell the story that in all the years golf has been played there nothing has been killed except a "cuddy."
Then again, they didn't use 460cc clubheads and ProV1s back then ... .