If it can't be understand by the average player, then chances are its not very good GCA.
I think there are MANY courses that can't be understood by the average player.
If they are only average at golf, why would we assume they automatically have high enough architectural skills to figure a course out?
Some will, some won't-doesn't make a course poor if everybody can figure out the challenge.
As Sean points out Palmetto is a perfect example.
Most average golfers LOVE nearby Sage Valley over Palmetto with its obvious cut and dried hazards, super green fairways and modern shaping.
They leave Palmetto wondering why they've scored so poorly after playing such an "easy" course,and talk negatively about the "unfair" greens and quirky holes