I would expect that a golf course construction is relatively rare event. And there is definitely no explosion of new golf courses. Total DC power consumption growth is practically exponential for the last 5 years.
That's just status quo bias, given that they're an ongoing source of water consumption. "oh it doesn't matter that [thing] is guzzling water, because it's already there!".
This whole thing is a sublimation of vaguer anxieties about AI (which are perfectly rational!) into areas where people feel like they can make more concrete objections that are likelier to succeed. The water thing is completely fake, whether people think so or not.
I think it’s pretty reasonable to conclude that their beef is not really with water usage as much as a general hatred of AI, big tech, etc, and water usage is an easy thing to focus on.