Twitter's decided they've got the gold standard in applications, and are essentially telling aspiring devs to eff off: "Developers ask us if they should build client apps that mimic or reproduce the mainstreamTwitter consumer client experience. The answer is no."
Having a bunch of smart people working for your company is good! But having all the smart people working for your company? Well, then your only option is to make deals with dumbasses, and nobody wants that!