I made a post a few back where I said we need to define a low standard player, probably if we agreed on that we would all be agreeing more on playability for ALL.
The pro's need to be tested almost to a point where the enjoyment level is virtuall hell for a low standard player...taking things to an extreme lets think about Augusta set up for the masters.
I'd say PGA west, Sawgrass are frighteningly difficult for the low standard player. Here in the UK, The Belfry is a -20 under course for pro's but many cant make the carry at the 18th and could not complete a medal scorecard. The Key thing in these courses is water. Water on GCA is ofcourse a dirty word, but water is a key like for the majority of modern golfers and newer courses, not all new courses will be on beautiful choppy sandscapes.
I like Sean's idea of minimal bunkering, but if you have courses where a low standard and a pro are going to play you might have a 150 yard range with which a pro v a low standard player are going to hit it. Yes you can factor some degree of back or forward tees, but its still hard to cater for bunkering, hence the need for multiple bunkering on fairways.
I think you could design a course playable for the pros up to 12 handicap reasonably easily, but when you start to stretch the paramaters so its pro's up to 18 or pro's up to 24 or 28 the excercise becomes difficult, perhaps even impossible. Another view is that you could create a course that ALL players between say 4 handicap and 28 could easier than say a pros- 18.
Perhaps we should not design courses for Pro's, they are the minority, the problem is when the phone rings you design for what the client wants and rarely does that client want a 6000 yarder that Auntie Mary can get round.
So, I dont think its a design flaw if you dont achieve playabilty for ALL, if you can get pretty near it its great, totally enjoyable for a low standard player and a pro maybe impossible in the strictest terms, but a parcel of land may crop up.