Some people feel they need alcohol in order to "loosen up".
I feel that some folks in addition to "loosening up" also tend to become obnoxious with alcohol. Furthermore, it does nothing for me as a host to have to worry about people imbibing too much at my party, and wondering how I will handle them if they get out of hand, and how I will accommodate them until I can safely get them home.
The best parties I have been to involve little to no alcohol, with people who were genuinely glad to be with the other people at the party.
Also the parties that had the most fun were ones where the activities caused laughter on their own merit, not by the masked laughs induced by alcohol.
I don't like to be a kill-joy or party pooper, but I think alcohol becomes too much a focus and the cost-benefit ratio is poor.
So bottom line, yes, I think New Year's Parties can be as much fun if not more fun, without booze.