The reason I brought up a 30 year old bartender, is because I know one that does just that. He spends about $500/month on weed. As a bartender, he makes about $2000/month. Therefore he spends about a fourth of his salary on weed. That's pretty ridiculous.
But your stereotyping, for every one guy that lives at home at 30 something and smokes pot I can show you one that has a drinking problem, one with a world of Warcraft addiction, and one with a jacked up family dynamic.
This doesn't make much sense to me. First of all, I'm not stereotyping anything. I'm just saying it's stupid to do drugs if all you're going to do is hurt yourself and/or family/friends. The guy playing World of Warcraft may not be getting laid (there's your stereotype), but he isn't risking an overdose, spending all the money he should be using to support himself or his family, or partaking in other criminal activities to obtain more drugs. As for the drinking, same as drugs. I enjoy throwing back a few beers here and there. I've gotten wasted plenty of times, but I don't risk everything to be able to drink.