You're right that it's just a name, which means it's within Tesla's power to not call it "full self driving". Like maybe keep the word "full" for when it's better than "full self driving brackets not really".
The reason it's called that is so when you're buying the car, you can read "full self driving", the salesman can call it "full self driving", and then you can get excited and think you're getting full self driving and pay stupid amounts of money for an iPhone on wheels.
It's also so Musk can get up on stage and lie for years about how you'll be able to go coast to coast while you sleep by the end of the year or whatever it is. Having a bunch of warnings in the software setup is not enough for someone gargling Musk's jizz to cough it up and see it for the bullshit that it is.
You can give us all this extra info but you can't change the core reality that the name is a lie.