They're not even trying to have a coherent vision for Twitter. You can't be "the world's most accurate real-time information source" if the content is "unfiltered." It's not possible. It can't even happen by accident.
@maxkennerly "Have you ever been talking with someone particularly insightful and thought, you should have the freedom to speak your mind" isn't so much a dog whistle, as an entire damn dog orchestra, complete with dog timpani drums and dog cannons.