The problem with this line of reasoning is that the general public has an inaccurate understanding of what airplane autopilots are capable of. The belief that modern airline pilots just push a button to turn on the plane then take a nap until the plane lands is widespread.
In naming their system after a system the public has a poor understanding of, Tesla is being misleading.
I agree that 'co-pilot' would also be a very misleading name.
I think they should avoid these sort of airplane analogies entirely and just describe features as they are. E.g. call lane assist "lane assist", call adaptive cruise control "adaptive cruise control." These are terms that reasonably convey what the systems do, without exploiting the public's general ignorance of how airplanes work.
Etymologically though, the co-pilot is pilot along with you and supports you, while the auto-pilot is a pilot by itself, independently (dare I say: autonomously).
"Autopilot" remains a very misleading term in the car context.
That’s my point: what happens to be the case in actual aviation is in some sense the opposite of the words‘ connotations. So, they’re very misleading terms. Which becomes problematic when marketing a powerful, but limited technology to the mass market.
In naming their system after a system the public has a poor understanding of, Tesla is being misleading.