The Greeks drank it that way because it more or less sanitized the water. The Greek national drink is Retsina, wine with pine resin. The Mycenaeans also enjoyed his (based on archaeological remains), as well as a mixture of beer, wine, and mead. A friend of mine tested it, found the ratio was 3:2:1 or 4:2:1, this was just with wine I believe, rather than retsina.
The Germans definitely drank it for the antibacterial properties. Better to be a little drunk all the time than dead from living downriver of everyone pissing in the stream. It’s an historical fact.