Dry counties in this country will remain in existence as long as there are communities against the sell of alcohol. There is not really anything wrong with this, as it is not necessarily against the consumption of alcohol but the selling of it in a specific community. Although a lot of these laws and sanctions on the buying and selling of alcohol are archaiac and don't make a lot of sense there still are some that serve a purpose.
Dry counties are dry for any number of reasons. Ultimately, it is the choice of the county, and since most of these counties are in the south, which is known for holding on to it's state's rights, dry counties are going to be around for a long time. While dry counties might be an inconvience to residents, they can still purchase liquor in the next county over.
Each and every county here has a set of rules they themselves want to live by. Generally speaking, it is a free country and if individual counties in this free country want to stay dry, then they are certainly allowed to do so. It is their right to make their own legislation to fit their own needs as long as they aren't trying to force it on their neighboring counties, and people are free to come and go as they please, there is no need to worry about it.
Dry counties, meaning counties that do not allow the sale of alcohol, are not something that will exist in the future because it is a ridiculous law. Even if counties are dry, people will simply go to the next county over to purchase alcohol. This defeats the purpose of dry laws and results in a loss of revenue for the county.