Well, the platform is not just about client apps, people use Twitter's data and features for all kinds of things. You're welcome to build on the platform if you've got a good idea.
Frankly, it should be a lot more about client apps and new ways to use the information in a personal manner instead of creating an API that looks for all the world like something I can use to automate my support staff on twitter and fire a bunch of people.
Twitter is so afraid of losing their users that it's becoming a self-fulfilling prophecy.