I'm not sure what point you're making. I didnt endorse data caps in the slightest.

Additionally, your example is awful. A person who is at the window all day is almost assuredly a burden on the "window" any time usage peaks. The window is by definition now a single user smaller at all times, and his presence at this window is enlarged like that of the morbidly obese. Multiple "normal users" could likely occupy the space he has taken throughout the day. Maybe it won't matter during off hours, but at peak he's a still a predictable system burden. Data caps are a simplistic way to discourage loitering.

Data is in fact a physical entity. By metric of electrons or simply by system design for throughput. A realistic pricing scheme ought to charge a minimum price for all users because every home connected has an associated infrastructure cost and a scaling price at peak hours because usage at those times has an associated cost as well.

Either way, it would still be cheaper than what comcast or whoever else charges and likely superior service.