Commodification, I suspect.  Based on the Google-cars I see traveling my Palo Alto neighborhood each day, my hunch is that the product itself is polished and the technical challenges well-understood, which means pricey tech leadership is no longer needed.  

If other IoT products are a guide, once a legacy mass market product overcomes the technical challenge of getting connected, the engineering magic is done.  We're then left with the grind of production efficiencies, regulatory hurdles, and finding traction with go-to-market strategies and dealer economics.   

Sure, the IoT world is going to be a tectonic shift in how we live, but those shifts aren't always earthquakes.