I have never played CP, but...
Machrihanish is well-known for having something of a dull finish. Holes 17 and 18 are par 4s (17 medium length, 18 quite short) over very bland terrain, and nothing like the heaving dunes you encounter over the previous holes (even the two par 3s that immediately proceed those, while not set in the dunes, either, are very good, strong par 3s with challenge and strategy.) That the chief challenge on 17 and 18 comes from an artificial source (OB all the way left, separating the course from the adjacent relief course) makes it all the more contrary to the natural demands put on the golfer in the first 16 holes.