Twitter's basic problem is that they opened up to third party clients back while they were still growing, and those third party clients quickly outpaced them in

Twitter's basic problem is that they opened up to third party clients back while they were still growing, and those third party clients quickly outpaced them in new usage features. Twitter has been trying to reign that in since (various things their official client can do is not accessible via the public APIs), but they can't just drop their third party support or they would see the usage rates dwindle in no time flat.