I assume Apple only cares enough about the anti-stalking feature to avoid significant negative press. As others have pointed out, you can buy small GPS trackers without anti-stalking features already, and those will only get smaller / better battery life over time.
Or, perhaps Apple only cares about the anti-stalking feature up to the point where it makes the product impossible to implement, because both have the same use case (finding). There are many AirTags in my family, and I'm constantly hearing beeping and getting notifications that I'm being followed, because my wife is sitting next to me, with her purse on her lap, and her keys, and her wallet. And guess what, you can't "trust" someone else's AirTag. I can't permanently turn off the notifications, because stalkers would do that too. The amount of anti-stalking that's present is so annoying as is that I'm probably not going to be buying any more.
In your opinion, what else could Apple do here, assuming you're familiar with the product?