LinkedIn is pretty much the only social network out there where the average person has a shot at a little reach for their posts.
Even if it’s just past and present colleagues and various acquaintances, I actually have an audience of people who are sometimes interested in what I have to say. I can't say that for any other social network.
Ignoring the political issues, my problem with Twitter is more prosaic: the character limit is too short for basically anything of substance. I really don't like the thread style it effectively forces.
(Oh, and the new name is unbelievably stupid. I ain't never calling it that.)