The answer to your question is in your statement. Most communities don't have "many reasons" to favour prohibition, in fact most communities don't even have one. Yes there's the idea that no alcohol = no alcohol-caused problems, but people don't assume they will have a problem when they start to drink.

In my area, the only dry communities are small towns with strong Mennonite backgrounds. And in every one of those towns, there's a bar right outside city limits, or in the next town over, where people in the dry community go to drink.