American Airlines for example is indeed just an American airline. The Container Store, Vision Center, General Motors, International business machines (IBM), the list goes on.
Even Microsoft is just a contraction of their original product, microcomputer software.
Hopefully that was also a family suggestion because I can't think of a more sloppy name than "Microcomputer software"
That's not the reason they can't. They can't register the trademark because it's a descriptive one.
If I try to trademark "hacker forum", an EU trademark officer will reject it not because my website doesn't have hackers on it, but because it's descriptive and prevents others from starting hacker forums.
So
> They could call themselves... ClosedAI
is also incorrect, because it's descriptive as well.
Not the issue. Per the ruling even if their AI was open they still couldn't have the trademark.
There were even some legal battles between them, see https://en.wikipedia.org/wiki/Apple_Corps_v_Apple_Computer
Apparently it ended with Apple Computers buying the trademark from Apple (record company) and then licencing it back (weird but ok).