Sometimes a UX team is forced to follow orders from someone above their pay grade. It could be an MBA leading a new feature that wants their button in a specific spot to increase their own metrics. Or someone higher up who "has an idea." Who knows what happened with Tesla though.
I'm presuming no UX team anywhere has stated "We're done here, there's no way we can improve on this UI". Hence to keep busy changes need to be made. Same with Health and Safety requirements, once a team is in place H&S 'creep' is inevitable. I once worked on a risk assessment for a laminator.
Good UX members won't stick around if they believe something is finished. But someone above them is always mucking something up, so there's always a problem to solve.
They should be held accountable along with the decision makers if people die or are injured. The lack of consequences allows these decisions to be made without user testing and can harm people needlessly.
This is exactly why I think there should be an engineering license for software developers in life critical things like this. We don’t allow civil engineers to build bridges that kill people, neither should we allow software developers. If you’re writing angry birds or whatever, you can do whatever. But if your software is in a car, and it kills someone, you should lose your license to practice.
So many things are monitored on a Tesla, it would be interesting to see if there would be any consequences from a black box style recording where you could see that someone crashed 1s after pressing the screen struggling to find the demister.