Depending on the stage of life you’re in, BYOB parties can either be commonplace or a rarity. If you’re at the time in your life when dinner parties are more collaborative affairs, where one person hosts, but everyone else is expected to chip in, requesting specific things for people to bring is completely acceptable. Think of it more as a “dinner party by committee” than one person throwing a shindig and hosting.
However, if you’ve come to the stage in your life where hosting a party means you are in fact just the host, requesting your guests to BYOB their drinks as a quasi-entry fee to the affair is indeed rude. As the host, you should supply the food plus beverages, and accept that most will still bring a gift — something everyone should do unless they, too, want to be labeled as rude. And if that gift is a bottle of something to drink, it’s up to you to either choose to open it now, if it goes with the other beverages you decided to serve, or open it at a later time.