An interesting viewpoint is to look at other professions. For instance, it is a matter of some contention in Ireland that there is not one but two bars in the Dail (our parliament/congress house). Why should lawmakers need to drink during work hours, people say, I don't do it in my job in the civil service, digging the roads, arguing cases, or whatever. And in one or two long sittings of the Dail in the last couple of years it was clear that some if not many of the TDs (lawmakers) were quite drunk.
Would you approve of this? And if you didn't, would you think that you'd be offering the same kind of insult to those you serve if you indulge yourself by drinking while you perform?