The whole reason the OEM auto companies have been so much slower than Tesla on many of these technologies is that they have a century of experience integrating technology into vehicles and testing and developing them over generations of model designs to ensure safe and reliable operation as well as recognizing that if they put tech into a vehicle, it could be on the road for 20 years. A time scale Silicon Valley never has to think about. Certainly there are cost considerations, obviously Tesla could not take over the whole auto market at their price point, the OEMs have to consider their entire product line including vehicles whose profit margins are razor thin.
Obviously the auto companies aren't always great at getting this right, but they certainly know how hard the regulatory and public opinion hammer will land on their heads if they play fast and loose with safety in a life-critical application like operating several thousand metal and plastic parts flying in relatively tight formation down the highway. They are much more risk averse than Tesla and the reason's why are starting to become apparent.
Driver assist systems when combined with an experienced driver make the car vastly safer, but trying to take the human wetware out of the equation at this point is premature.