No need to give up. Just acknowledge that is a hard problem whose success date is notably indeterminate. Then stubbornly refuse to talk about future features and only talk about one's already shipping today. If the future is going to arrive so soon, why bother to break in advance? Let everyone be amazed when it does arrive.

I love the autopilot feature, but the cars are still great without it. Tesla can be very successful and sell a lot of cars without any more self driving features.

I think that's one of the main problems I have toward Musk. He started with a strong 'hard science' stance on problems and all of a sudden he became just another salesman. If he just stated where they were .. I'd be less annoyed. But maybe it doesn't mesh well with PR