If this is a serious question, I advise some long and hard introspection.
Why would anyone waste their physical and mental well-being by consuming poison?
Many people enjoy the taste and/or effects of alcohol, and consider the tradeoffs acceptable.
Also, in some places and times, moderate consumption of e.g. wine was/is believed to be healthful.
Tastes good, lets you drink socially if you don't want alcohol
Ya it does seem kind of silly. If it doesn't have caffeine or alcohol might as well just drink water or something diet. Your not getting much for your consumption of (usually) refined sugar or high GI carbs. Maybe in a social setting to pretend, but mocktails have existed for years?