The law is mostly about the general rules. Legal analysis tends to be about edge cases, only because those tend to be the ones that are interesting to fight about. The general rule is that you can pretty much arbitrarily revoke license to use your private property.

Vis-a-vis beach access: the exception arises in that context because the waters of a state and all submerged land and land up to the mean high tide line are public property. Thus, while you remain free to revoke license to use your property arbitrarily, you can't use that to unfairly monopolize access to public property.