There are lots of other reasons. For example, in a given area, when wages go up, rents invariably rise as a consequence, and with increase taxes based on those raises, workers may end up earning less.
Lessors also tend to jack up prices around universities, military posts, and other places where they are assured renters who need to live there.
Yes, the economic law of supply and demand is still in effect. Still, where there is a demand, and it is technologically and economically feasible, someone will usually create the supply.
I think there would be a demand for inexpensive dormitory type housing without the control by the university, military, or other concentrators of population. It is possible that land nearby has become so valuable that rents need to be high to pay for it, but I believe that zoning ordinances have driven up housing costs considerably.