As it turns out, American college students drink in far unhealthier ways than European students. It has been suggested that it might have something to do with the absurd legal drinking age of 21.

That's irrelevant since the prohibition came after the addiction was established, not before.

Also see: Alcohol, Cannabis, Portugal's decriminalization etc.

I didn't mean to imply it wasn't sometimes worth it anyway; I apologise if it read that way.

I just meant that you shouldn't be surprised when irregular/unpredictable access to something makes people eager to take every opportunity, and that it's a factor to consider in your strategy.

I think a big difference with the AA is that usually the people going there have decided they (on some level) want to stop drinking, rather than that being an externally imposed restriction.