Water "cooling" is actually a misnomer. The water is merely a heat transfer system. Much like a copper heat sink is a heat transfer system. Nobody would call that "copper cooling".
Are you saying cooling isn't a "heat transfer system"? Your distinction doesn't make any sense.
We don't call it copper cooling, but we do call it a copper heatsink, and it does cool the object on which it's attached by transferring the heat away from the object in question.
While a heatsink doesn't reduce the temperature below ambient temperature, that's not a necessary qualifier for "cooling".
So.. No, water cooling is not a misnomer. Water is used to cool the object in question.