This is not (only) about being green. Electric cars are a pleasure to drive, they are less costly to maintain and repair (far less moving pieces), they are cheaper to run (at least in Europe, don't know in the US), and you can charge them at home (this is more of an advantage in the US than in Europe).
Even the most anti-green buyers will prefer electric vehicles in ~10 years (if no sooner)
Developing a new car model is not done in a few months, they take years. So it's understandable that car companies start to plan the future now.
They also don't know if the demand will follow an S-curve and when. Disruptive changes are difficult to predict (probably predictions 11-12 years ago said Nokia would still dominate mobile phone market in 2017 :D)
The demand will grow as battery prices go down, and range of electric cars increases. When an electric car has the same price and range than a petrol car (and probably before, as maintenance costs for an electric car are lower), there will be no rational reason to buy a combustion car. It's only a matter of time
Even the most anti-green buyers will prefer electric vehicles in ~10 years (if no sooner)