The data tracking service is also determined by the user, it is directly tied to the “AirTag’s use” that you mention. Additionally, Apple notifies the user very clearly, in more than one place “clearly states that AirTag is meant to track their own belongings, that using AirTag to track people without consent is a crime . . . “
The company does not have, nor can be expected to have, an understanding of the individual consumer’s tracking intent - i.e., little Johnny’s backpack, your luggage, or (wrongly) your wife. They have put very reasonable safe-guards into the system to alert people of being tracked unknowingly, serialized the devices and required an activation of the Tags to be linked to an Apple ID. Then add precision location and alerting features (including consideration that the speaker may have been disabled) and cooperation with law enforcement to release purchaser/account info. This has far more protection then tracking devices you can easily buy off of Amazon (try a simple search on “tracking devices” - yikes)