Here’s an interesting article from Inside Higher Ed titled “A Skeptic’s Take on Academic Blogs.”
Here’s my favorite piece, on that supports the decentralized argument. The author is talking about moving from a decentralized form of blogging (people have their own blogs) vs. a group blog format.
I have come to the conclusion that what was so good about the original disorganized format of the University Without Condition conversations was precisely that it was so decentralized. This feature allowed it to escape one of the major pitfalls of conversations based in blog comments  the inherently hierarchical nature of the format. In blog comments, someone has written out a thoughtful post in what they will often regard as their own personal space. They have an established community of commenters who are, for the most part, sympathetic to the author’s point of view. Thus, when someone comes along and starts criticizing the original post, there is naturally a temptation toward “circling the wagons.†Additionally, comment forms are generally cumbersome and difficult to use for in-depth conversation  with the paradoxical result that one will either dash off a quick comment that by definition cannot match the rigor of the original post, or else an overly long comment that people will experience as an imposition. Having various people responding on their own personal blogs rather than in comments gets around all these problems  the conversation is decentered, not localized to anyone’s “turf,†and people are more likely to write lengthier, more thoughtful responses if they are producing it for the sake of their own blog instead of writing something that will be hidden away in some obscure corner of someone else’s comment sections.
There’s some great insight, capturing a bit what I’ve learned being involved in an academic blog.