incompetence has nothing to do with it; it's about power. tesla's posture with respect to the users of its cars is that tesla controls what the software running on the cars does; the users do not have the right to study, modify, copy, or redistribute the software. unsurprisingly this incentive structure means that tesla has no incentive to protect the users' data from tesla employees' abuses, since the users can't study the software to detect it and wouldn't be able to modify the software to stop it in any case or redistribute their modification to other users
if there is software running on a computer in your house or your car, it is absolutely essential for that software to be answerable to you in these ways, not to the manufacturer of some product. currently that perspective is far outside the overton window, so we can expect to see increasingly egregious abuses like this for decades