"But Turner contends that a "band of thugs" - Toltecs, for whom cannibalism was part of religious practice - made their way to Chaco Canyon from central Mexico. These invaders used cannibalism to overwhelm the unsuspecting Anasazi and terrorize the populace into submission over a period of 200 years."
"Turner says the culture's carefully constructed social fabric began to tear. Finally, the Anasazi fled the oppressive cultists and sought haven deep in remote canyons. The next time any part of the culture appeared, these Pueblo people were found to have constructed elaborate dwellings adhered to the sheer sides of cliffs."
"Generations of scientists have postulated that such suspended villages - located far from water - represented a fear of a great foe. Turner suggests the Anasazi took up these defensive positions against a horrible enemy - the evil that had infiltrated their own people."
The only thing that makes sense to me is that they were defensive position, because they were certainly hard to get to.
It wasn’t much of a strategy, though, since they grew their crops in plain sight above the cliffs, and they certainly couldn’t protect them from within the cliffs. And, even in peace time, these folks were doing a whole bunch of rigorous climbing just to accomplish routine tasks.