Without the kinds of explicit committments in licensing or API access that no board of directors would ever go for, I have to think they're sowing the seeds for a round of acquisitions.
You hit the nail on the head. Twitter built an empire on the backs of devs using their API, then left them to rot or actively burned them directly as soon as the money got real.
As they say: fool me once, shame on you. Fool me twice, shame on me.
http://www.wired.com/2014/10/twitter-fabric-sdk/
It's... fine. But given Twitter's history of dev antagonism I am not about to create apps that rely on them as a backend. Sorry.