But there is zero reason why I shouldn’t be able to run a 7-Eleven and sleep on a cot in the back if I so choose.

Why can't you? I don't believe that there is any law saying you need to have a home in a residential zoned area (anti-homeless laws say that you cannot use public space as a home).

As far as I know, zoning laws just say that you cannot sell or rent out a property in a commercial district as residential. That is a false advertising/minimum allowable quality law, much like you cannot sell the meat of an a diseased animal. Commercial areas likely don't have the infrastructure (schools, utilities, safety) for people to live in.