Like most critics of Twitter (Twitics? No. Definitely no), he's completely missed the point.
He seems to be expecting Twitter to be a drop-in replacement for his blog, but it serves an entirely different need -- at least, I suppose, when you have real-world friends on Twitter. Being able to broadcast messages to your friends is pretty powerful. My standard example use-case is "I'm going for lunch at X in 10 minutes. Anyone nearby?". Try that with a blog.
yes thats the point being made there. Twitter is not really a medium to express any "knowledge" as such. It is basically used to convey short lived information.
The author does not say that twitter aims to be a replacement for blogs, not really. It is a common concern that is expressed at many places that people who blog often might find twitter more attractive.
He seems to be expecting Twitter to be a drop-in replacement for his blog, but it serves an entirely different need -- at least, I suppose, when you have real-world friends on Twitter. Being able to broadcast messages to your friends is pretty powerful. My standard example use-case is "I'm going for lunch at X in 10 minutes. Anyone nearby?". Try that with a blog.