Weed has zero culture around it. 420 and dreadlocks, that's about it - and there's only one stereotypical weed user and its the unemployed waste of space with no aim or drive in life. There are also no socially acceptable occasions to use weed.
Alcohol is very broad with all sorts and types of the stuff, suited for different circumstances and is easily woven into widely accepted social engagements such as eating Italian food or celebrating the New Year. The worst stereotype of the alcohol consumer is the drunkard which also embodies that of the stereotypical weed user, but otherwise the typical people who drink alcohol also includes a wide variety of culturally engaged and sophisticated people such as wine tasters, whisky reviewers, or the classic 'real ale twat' (the best one.)
It's not a coincidence that when I speak to a weed user about alcohol he only talks about commercially available lager and only shows an interest in the alcoholic content - he just wants to be inebriated, which is after the only recreational function of weed. There's no taste involved when it comes to weed, the user just wants to get high, just as the drunkard just wants to get drunk. When weed users think they have a point about alcohol being a socially destructive drug, they are actually pointing at themselves as their physical evidence.
Finally, weed is addictive no matter how many smackheads claim otherwise. Get a job.