Alcohol never tastes good initially. Taste for it develops alongside appreciation (though on a sort of unconscious level) for the effects of the drug. Namely, alcohol makes you happy. It actually does a pretty poor job of this, among the other drugs. Insofar as -- I imagine -- the point of all of your friends, work, social life, etc. etc., is so that you can feel happy, it makes sense that some people do drugs/alcohol. It makes them happy just like pizza and friends do.
--someone who didn't understand why anyone drank or did drugs a year ago