One of the problems has been the huge amount of expensive infrastructure that will have to be abandoned and the assets stranded by a transition to a clean electric economy and the companies involved and politicians who support them are not prepared to face that.
This may all be about to change and will be market driven so that car companies and electricity companies will have to move rapidly to the new technologies or fail. It took ten years between 1910 and 1920 for the horse powered transport to be replaced by cars and we are entering a similar but bigger period of transition and disruption. Watch this half hour video for an in depth appreciation.
https://www.youtube.com/watch?v=Kxryv2XrnqM&list=FLiUwiBc_bp0xCGnsJ2LL2Tg
In brief, the price of solar power and wind is coming down so fast that it is cheaper than coal or oil, batteries are getting cheaper and more efficient so that they can deliver stored energy when we need it and cheaply, an electric car only has 18 moving parts compared to a petrol one having 2000 which makes them cheaper to manufacture and operate and more reliable.
https://medium.com/@cdixon/eleven-reasons-to-be-excited-about-the-future-of-technology-ef5f9b939cb2#.6j1mhqivh