I think you misunderstand the US system.
The image below shows the airspace situation as shown on the US sectional chart around Savannah Airport(KSAV), an airport with approximately 6.5 times more movements annually that Williamtown. The Class C airspace is shown by the maroon lines. Significantly there is an upper limit to the airspace at 4100 feet. Above that height the area is Class E which in the USA does not require a radio or a transponder* for VFR flight. The consequence of all of this is that the airport does not prevent movement of aircraft like Williamtown does.
*slight correction. In Class E you do not need a transponder in the USA but above Class C as in this case you do.