Corollary to my theory: most people who complain that a course is unwalkable may or may not be a wuss.
I'll give an example of a course that most people would consider unwalkable where walking, for me, greatly enhanced the experience: Morgan Hill in Easton, PA. K-Harris and I played it last April. Before the round, Kyle says, "should we walk or take cart?" After waffling for a bit, we decided we should walk, despite the fact that the course is through a housing development with a couple hundred feet of elevation change. Man, that walk was a blast! It was really a golfing adventure, an outdoor sport in the 19th century sportsman's sense of the word. My favorite part was the hike from the catcher's mitt 12th green (right across the street from the Black Cat fireworks store) up to the 15th tee. With the clubs on my back, I felt like I was on a hike in New Hampshire. It was an experience that I'd never had before on a golf course, but it was great. If we had decided to ride that day, on a course many would proclaim "unwalkable," we would have been robbed of a rich golfing experience.