If you were gay, it wouldn't have to be a singles bar. It would just be any place where homosexuals hung out.
I live in DC. Dupont Circle is the "gay area." A lot of businesses in the area have a high percentage of homosexual patrons. Imagine walking into Starbucks knowing that a goodly percentage of the patrons are willing to have sex with you. Unless you were willing to completely segregate yourself from the gay community, you would constantly be exposed to temptation.