Don't get me wrong, I'm not keen on getting tracked, either. But I can totally see that from a company's perspective, if you can make sure that only people who are interested in your product actually see the ad, that's better. You don't annoy people who aren't interested (not everyone in a rich neighborhood cares about a BMW ad, some already have a Tesla) and you increase effectiveness.
Because "better [for advertisers]" is a euphemism for "worse for advertisees".
> Why stop there?
Because it's deeply unethical.