Couples prefer having non-alcoholic weddings for various reasons. However, the most potent reasons are that your religion does not allow it or either or both of you do not drink. Some couples might have loved ones who are abstainers or battling alcohol addiction, and they wish to hold an inclusive wedding without alcohol.
Many couples want to avoid alcohol because it heightens emotions that already run high at weddings. Alcohol has been popularly known to place a serious dampener on wedding festivities, from vomiting guests to drunken brawls.
Another reason is that the bride might be pregnant. Moreover, with alcohol in the picture, it will not be safe for guests to drive back home or to their hotels. Plus, no alcohol means no hangovers, and your guests will wake up the following day with a fresh mind.