Lots of alcoholics don't do the bar scene. That doesn't mean they aren't alcoholics. Who knows if they are or aren't or are on their way. The point is, you don't have to drink unless you want to. I would ask why they care how much I drink and then tell them to mind their own business. If they continued, I'd just tell them to eff off and leave. Problem solved. Who wants to be around jerks like that anyway?