What do you do with this information? Do you create multiple MVP games and then complete development based on wish list metrics?
I know publishers like Playway do exactly what you describe with all of their <insert niche job here> Simulator series of games, but it's not my thing. I use my wishlist counts to check I'm on the right track, to keep encouraged when development feels like a grind, to help justify putting a certain amount of $$ towards its development. If I was really struggling to get wishlists I would seriously consider changing the game's presentation substantially, or changing to work to something else, but I've not yet been in that situation. But in that case it would be a pretty decent signal that something about how the game looks isn't chiming with potential customers.
There are other useful metrics too, how many YouTube views did the announcement trailer get? Did it get posted to reddit and do okay there? How many people have joined the Discord? And so on and on, so it's not all one thing.
Given the not-perfect-but-pretty-good correlation between number-of-wishlists to number-of-first-year-sales it's a helpful number to help budget/forecast my business.
But, it's harder to imagine how Steam wishlist counts lead to totally distorted accounts. Unless someone is botting your Steam store page and the wishlisters don't exist, they're all still potential customers, and 5,000 wishlisters means something and 50,000 wishlisters means something.
There's lots of conversation about 'quality' of Steam wishlisters between developers. For example, Steam Fest is an event that Steam runs every now and then with game demos and there's very prominent 'wishlist this game' buttons. It's generally accepted that these wishlisters are 'worth less' than if they come from YouTube or PCGamer or even other sources upon Steam. So if 90% of your wishlist count comes through Steam Fests, yeah, you probably do have a distorted metric to work with. But no, I haven't experienced this myself.