Comment by pmontra

Which brings up a different problem: personalized reading UI, personalized writing UI, how are those services going to pay their bills? Maybe they can sell access to their APIs but who's really going to buy that? Those services will die and will be replaced by some other service that will be born to serve those people.

Or, more probably IMHO, most people will keep using the standard UIs because they are ready and they need no work to build.