I think there is an equally big community of wankel enthusiasts, and an even bigger one for diesels. (Both of which I would very much prefer over EVs!)
And every one of those expansions takes development time ... so priorities gotta be set. I'm still hoping for diesels some time in the future, as they got a pretty big marketshare, while wankels and EVs (over the whole timeline) only played a minor role in the automotive industry.
Diesel ban by 2020? Where did you hear that?
That would be pretty much unthinkable, at least in Europe. Approx. 50% of cars here are diesels, in some countrys more or less.