If it was being used for evaporative cooling then the argument would be stronger. But I don't think it is - not least because most data centres don't have massive evaporative cooling towers.
Even then, whether we consider it a bad thing or not depends on the location. If the data centre was located in an area with lots of water, it's not some great loss that it's being evaporated. If it's located in a desert then it obviously is.