The problem with that is that station owners make more money from a strictly self-serve model. Therefore, even if the law required them to offer full-serve along with self-serve, they have an incentive to push customers to the self-serve model. That means doing things like limiting full-serve pumps, and ensuring that full service is absurdly slow (perhaps assigning the full-serve attendant tasks that require him to be away from the pumps).
If there were truly a way to have a legitimate choice between full serve and self serve, that would be great. But that is not the case. It really is an either-or situation.