Technically,yes;realistically, no.
It is harmful in terms of effects it has on the body, and the actions many participate in while drinking (impaired judgement leads to drunk driving, etc.), however, it really wouldn't be practical due to how common and accepted it is by a large amount of people ... Making it illegal would just cause the return of speakeasies and all of those wonderful '20s things.
So yes, it should be legal, however, it's virtually impossible to make illegal and it has been attempted before, and failed quite badly.