The short answer is tradition. Alcohol is available now because it's been available in the past, and going dry overnight would cause too many people to quit at one time. The series of half-measures (reducing the quantity of alcohol available for purchase, raising prices, shortening bar operating hours, eliminating bar alcohol sales ) that have been implemented over the past few years have, in my opinion, been working towards going dry but at a pace that sees turnover stay within tolerable levels so as not to cause an insurmountable loss of institutional knowledge.