Drinking is not the problem, drunkeness is. Of course, given that most parks have inexperienced personnel due to low pay and no benefits, the easiest way to prevent drunkeness is by not selling drinks.
To help both guests and employees, how about this as a condition of the liquor license? Employees selling alcohol get $2 extra per hour. But if they sell to someone underage or intoxicated, they lose the job. Give longest-serving employees with excellent work records first dibs on the gigs. That ensures that you end up with employees who have both the experience and the financial incentive to say no to people who shouldn't be drinking. And a few good employees get a pay raise, too.
Last year we went to the Mardi Gras parade at Universal Studio's. There was no control at all regarding the sale, and drinking of alchohol.
People were being sick in the street. One couple I observed left their young child so they could go across the street to buy their next beer.
The parks need to decide are they for everyone or adults only.
While other parks seem to get away with alcohol sales not hurting their image otherwise, those parks spend more on a daily basis on security, cleanliness and worker awareness. SF has a history of cutting expenditures in those areas, leading to overall decline. Adding beer sales will accelerate the decline as underpaid, ill-equipped staff try to deal with the "beer-induced idiocy" phenomenon.
Heck, they can't tolerate fully sober patrons who won't take off their hats as it is! How will they react to a drunk rider???
I was in the England Pavilion at EPCOT back in Sept, and was very upset seeing a group of young adults drunk and singing songs very loudly in the middle of the path. I hope that Disney security came by at some point, but I did not stay long enough to notice.
So its down to the drinkers to be responsible, but if they aren't, then security in place to fix it.
Six flags should look at other succesful venues if alcohol is introduced, becaus Disney & Universal have in controlled.