They still need to sell cars for the next couple of years. When they've mentioned autonomy and removing the steering-wheel (some) people get upset because they want a car they can drive themselves.

So if they tout the idea of people not owning cars too much that is will only antagonize people in the short term.

If the ownership model changes they can easily adapt. I think they are very aware of the car ownership statistics and how cars being shared is a fundamentally better model in most cases.