The reason physical space has any value at all is that there is only ONE of that given space. If / When AR becomes a thing that actually matters, there is zero chance that only one AR 'space' within a physical space exists, making it meaningless if someone took your physical space and used it for whatever they wanted to in AR. No single entity will hold a monopoly over AR 'space'. There would be all sorts of varieties, such as MS, Apple, Starbucks, TPB, you name it. As soon as that 'space' is available to anyone who gives enough of a shit to set up something in an AR, all value it may have held is lost forever.