Jon,
I've played golf with you and I know that you think nearly every course is walkable... if you define walkable as a course that can eventually be traversed given enough time and energy. Hell, you even walked Dismal River, which I would consider a non-walking course... although you did opt to play the 18th hole from the lower tee instead of climbing up to the stratospheric tee high above.
I played three courses this past week in Mesquite that I would consider some of the most unwalkable I have ever seen: Falcon Ridge, Oasis-Palmer, and Wolf Creek. They would make walking Dismal River seem a like a stroll around the local mall with your Granny. FR and O-P were two of the worst courses I have ever played... a complete disjointed mess of holes that climbed up and down hills with long stretches between them that were like severely snaking roller coaster rides. Could they be walked? Yes, but it would probably take a certified Sherpa, and oxygen tank, and about about seven hours.
Wolf Creek? Another Golden Tee video game inspired course filled with holes built for no other reason than "wow factor." Most start on top of mountainous terrain in order to provide eye-popping views. While not as bad as FR or O-P, Wolf Creek is some crazy sort of fantasy course... where someone would have to be doing some serious mind altering drugs to even want to attempt walking the place.
Why someone would want to play (much less walk) these kinds of courses is beyond me. They are horrendous.