... Twitter implements a distilled version of many problematic aspects of blogging. Namely, a one-to-many broadcasting system that serves the needs of high-attention individuals, combined with an appeal to low-attention individuals that the details of one's life matter to an audience.
The "A-list" phenomenon, where a few sources with a large readership dominate the information flow on a topic, was particularly stark. Since the numbers of "following" and "followers" are visible, the usual steep ranking curve was immediately evident. A highly ranked person is free to attack anyone lower down the ranks, as there's no way for the wronged party to effectively reply to the same readers.
Getting a significant followership and thus being socially prominent is also important. Hence, there are major incentives to churn out quick punditry that is pleasing to partisans.
I have tried Twitter. I didn't quite enjoy it, so I don't foresee becoming a regular user there. It's not clear to me what it was about Twitter that bummed me out; but it's certainly not the sociological issues highlighted by Finkelstein -- I really haven't thought much about them until I read his piece.
It's quite possible that I don't enjoy Twitter because I don't "get" it. That's okay; the Web does offer many ways of dealing with the online world, and we get to pick the pathologies we are comfortable with.