It seems obvious now but even 2-3 years ago I don’t think it was so obvious. Aside from Tesla, other auto manufacturers have just been dithering around.
Volume and demand for electric vehicles has not quite hit a tipping point, but just at the right time they've come out with the i3, which has really beaten Tesla in quite a few different aspects. Ditto the Ford Lightning or what have you.
IMO the car companies are actually not quite as naive as we've come to think. They robably have internal roadmaps ready for the next 10+ years of electric releases.
I expect they will ramp up to a "Tesla killer" at just the right time.