> why can't someone buy enough land and incorporate their own city?
Because you can't just incorporate your own city because you own land. In California, you need to convince the Local Agency Formation Commission for the county you are in, and, if your land is in an existing city, also a supermajority of the residents both of the land you own and the existing city from which you are splitting.
Because you can't just incorporate your own city because you own land. In California, you need to convince the Local Agency Formation Commission for the county you are in, and, if your land is in an existing city, also a supermajority of the residents both of the land you own and the existing city from which you are splitting.