A self imposed cap is effectively no cap at all. The city will have the full ability to make exceptions to their own rules and license whoever they want. It might add another piece of paper or meeting to the process for the exemption, but adding red tape is all it would be doing.

As an example of what I'm talking about, the Somerville licensing commission opposed Beer Works because the city had decided that the remaining licenses were only for areas in need of economic development, which isn't Davis Square. When a Korean restaurant applied for a license in a location directly across the street from the proposed Beer Works, suddenly the "economic development" restriction no longer applied.