You may very well be right.

I know I would never get a room as large as I get at the Rio (for free) on the strip with my level of play.

I tend to be a Stratosphere to Mandalay Bay guy myself, and I suppose that if they built a major casino/hotel/facility immediately south of MB, then perhaps it would stretch the strip, but I just find it interesting that the Hilton is such an anomoly in its history and location.

Maybe it has to do with Elvis.

I doubt I would extend the strip North (in my mind) because as I recall it, the strip basically devides just after or around the Stratosphere. Furthermore you fall off into a whole new world as you go North.