Sure, and I didn’t argue for or against the use of that term. The legal definition of theft varies by jurisdiction, but is not necessarily limited to physical objects (e.g. services). I have no idea whether it’s appropriate in this case (I’m not a lawyer), but feels more like copyright infringement.

Control is a part of ownership. If you don't control how something is used and by whom, you don't really own it. So either using it in unauthorized ways is in a manner theft, or Apple's "ownership" is not real ownership. I'm not sure what the solution is, but IP is a tricky concept no matter your position.

It sounds like Apple don’t even own it then if they can’t prevent people from pirating it.

It has nothing to do with actually preventing all infringement, but instead seeking enforcement in at least some cases. If a copyright owner is aware of substantial infringement and chooses not to pursue (or license) they may lose their copyright through genericization or other means.

(Caveat: I’m not a lawyer, but I learned broadly the above from an IP lawyer.)

I can’t prevent someone from robbing me, just make it harder for them to do so and have legal recourse if they do it anyway.

This still counts as “having control”.