Provocative thesis: email is an example of the failure of federation.

The API is frozen because of the gigantic size of the deployment. The API is inadequate. Spam has destroyed email as a result. We cannot fix it, because getting the API right early didn't happen.

@ceejbot Well, I don't know how you characterise success but it's obviously not by user adoption. And one could argue that it's the only metric worth mentioning.