Enjoying the responses thus far!
Sean--I'll touch on my sense of "problem" here differently. In my mind it has more to do about the perception of the differences (or to phrase it more strongly, an artificially construed gap) between classic and modern design. Touching on Thomas Dai's comment here, the age, exclusivity, or price of admission onto any course should not affect the quality of a course's holes or its standing in a critical analysis. Yet we all know that's not the case, and that, for me, is problematic. For example, if Pacific Dunes was the only course on the Bandon coastline, and it was a private club with a membership comparable to Sand Hills, my guess is its ranking would be better than it is now. Which, were that to be true, would be a fault of rater culture.
More importantly for me is that I think it would be a disservice to golf course architecture if either contemporary architects and/or players and raters are not operating under the belief that any new course has the potential to surpass Pine Valley, Cypress, TOC, Shinnecock, etc. That is not to say any particular modern course can or will do it, but if the possibility is a closed door in people's minds, we as a community are mistakenly keeping the ceiling too low.
John M--the passage you quoted was specific only to Ireland and Northern Ireland, but I understand your question. What I wrote implied that, though I personally think Portrush is the better course overall, the experiential value of RCD, in combination with the course, would lead me to pick RCD over anything else if I only had time for one round. In your hypothetical, were Pac Dunes or Ballyneal also available choices, then yes, given my own rationales I've laid out I'd be selecting one of the Doak courses to play in a single round scenario.
I don't find that as a slight to RCD. It's magnificent and provided one of my best days in golf ever. My point is that, after thinking about the course, I wanted to come to the defense of a couple modern designs that I find to be more compelling, even if consensus rankings don't reflect my views, and I wanted to probe that discrepancy a bit more deeply on the DG.