Dry wedding says I don't care to have alcohol at my wedding. Cash bar says I don't mind having alcohol, I just don't want to pay for my guests refreshments (which is tacky). IMO all food and drink options offered should be free.
Neither are tacky. The wedding couple has the right to have the type of wedding they want and are paying for. Way too many weddings, as well as other special occasions, are ruined with a few people who simply drink too much and can't control themselves.