If it were that simple,

then why would we need theft protection?
I believe that people should be able to easily adjust their property as needed, and some workshops are less helpful in that regard. Ideally, everyone could do it themselves by having a "master key" provided to the customer for each vehicle.
All the corresponding control units installed in the vehicle can then only be used elsewhere with this deactivation key.
Probably, this isn't done because then everyone would be in control of their own property, and you couldn't continue to charge extra money for things that should be considered basic.
