Most times if I'm offered booze, I'll usually say no just out of formality. Not like I need to be drinking anyway.
It's not evil though. It promotes stuffloads of fun (as long as you're not handicapped about it; it's not hard), but it's really not needed to get parties started.
I understand some people have a low tolerance for alcohol and get wasted pretty quickly on 1 beer, though. IMO those people just shouldn't be drinking then lol.