The bars are one of the reasons why they stopped doing it before.
They had a LOT of problems with drunk guests.
USH HHN is a completely dry event now because of it, and honestly, its been working out very well. I dont think I got hit once last year (and I certainly haven't been hit yet this year) but when I was at Knott's (which serves beer.. I dunno about mixed drinks) I was kicked, choked, punched, and one time pulled to the ground (by an attractive female, but still!)
And even from a guest perspective, I've been to Knott's sober, and I've been there drunk. I don't remember much from the drunk trip (except it was fun, I suppose) but if Im paying good money, I want to be able to remember it in better detail then just that.