You know what would make a lot more sense? Advising them to cut back and modeling responsible drinking behavior. Instead of ordering them to abstain and screaming when they don't, share a few beers with them and then stop.
A young adult's brain is fungible. We'd all like to believe that we think for ourselves and are immune to social pressure, but none of us really are, and the young are less resistant than we more ossified older folks. Their open minds are actually a minus when they're flooded with propaganda telling them that they must cease drinking alcohol forever or else they will surely become drunkards.
Nobody is literally born an alcoholic. Some are born with a predisposition, but the overdrinking itself is learned. If that were not so, it could not be unlearned.
These people have 50+ years still ahead of them. Virtually all of them will, at some point, drink alcohol again. Priming them to overdrink is insane.
Contrary to popular belief, most overdrinkers can and do cut down on their own. Moderation is a more common outcome than either abstinence or continually worsening addiction. Unless, of course, we catch people at vulnerable times, knock them off balance, and work hard to convince them that they can never drink normally.
Our zeal for abstinence creates alcoholics.