I've been the one sober guy at a birthday party while everyone else was drunk (not a fun experience, I can tell you that) and while I personally don't drink (or smoke or do drugs or have casual sex or pretty much anything that can be labelled a vice) I don't look down on or feel superior to those who do, if you want to do it then fine, I never really felt any urge or desire to try it so my opinion on the matter can be summurised as 'don't really care'.
Yes, there are the obvious health issues, yes there are the potential dangers associated with any instances of being in an altered state of mind and yes it probably costs a metric fuck-tonne of money to buy more booze but if you're going to get specific and nit-picky about it then you can point out the flaws and problems with everyone's preferences and likes (for those of you who are health nuts and enjoy your exercise, no matter how healthy you are or how well you keep yourself in shape you will end up dead like the rest of us, thank you and goodnight).
As for people who proclaim the 'social benefits' of alchahol, please be quiet. I know that being slightly tanked can make for some very memorable nights and a lot of fun with your friends but we all know that it's not because booze is some miracle wonder drug that suddenly makes you friendlier or more charismatic (again, I've been the sober guy at a drunken party, people who are tanked are funny more in the 'laughing at you' way than the 'laughing with you' one).
I know this is a bit of a cookie-cutter, goody two-shoes point to make but if you do need chemical assistance in order to be social and have a good time then it does sort of suggest that there is something wrong with you as a person.
I'm socially challanged and have a hard time talking to people (I used to be even worse though, even making eye-contact was difficult for me), the only reason I've gotten even slightly better at socialising is because I forced myself into social situations and made an active effort to be more social to compensate, so I'm not really sympathetic to people who claim that they need booze in order to be social and talk to people.
If you want to drink then fine, but only do it because you enjoy doing it, not because 'it's social'.