Matt Ward,
There is absolutely no problem "playing the course on a daily basis". I grew up playing it a few days a week, and it only serves a reminder that you have to keep your wits about you at all times - like all great courses (PV, Merion et al) there is very little rest for the mind when taclking the links at Portrush.
Yes the fairways are tight in spots, but so was Merion, and I didn't hear you complaining about those. The fairways on holes 1, 4, 5, 8, 9, 12, 13, 15, 16, 17 and 18 are not "too narrow". Yes, #2 and #7 particularly are narrow given the difficultly of the dogleg, but golf should demand something of you with every club in the bag.
Portrush demands that you drive it straight, hit accurate irons (or the ball will catch the slopes away from the green) and the putting surfaces are very interesting and varied.
I'm sorry, but I have to disagree with your assessment. And as far as weak holes go, if you can find more than 2 for me I would be VERY surprised!!!!!!!! That means 90% of the course is world class, which is why it ranked accordingly.