I can see why this happened. From a marketing standpoint, "hey wow autonomous cars for free for our existing customer base! Whoopdydoo climb TSLA climb!" From a liability standpoint, "hey, we just told your car to drive itself, now read this longlistofdisclaimersheywaitwhereareyougoing-" Elon Musk does not listen to lawyers.
The thing that gets me is that every obviously AI application I've ever written has taken months to get users to trust it. I try very hard never to say the "a" word when I write one now because I know I'm in for months of "explain this" and "what would it do in this bizarre hypothetical that will never happen and/or cannot possibly happen" if I do. Driving your car, on the other hand? Look ma, no hands! Obviously I need to work on more applications that can kill you.