I could go on and on and on on "Death of a Blogger" and the general ed-tech blogging malaise.
I'm reminded of a panel I attended at SXSW 2004 on "The Future of Blogging," which included danah boyd and I think someone connected to Six Apart. Given the way the conversation went, I thought it should have been titled "Web Publishing for People Who Don't Want To Publish on the Web," because the consensus on the panel was that that was what the mainstream wanted. They were right. Most normal people don't want to publish quasi-permanently to the whole world. They want to write for their friends, perhaps people they have some professional relationship with. These people are happier with social networking sites than straight blogs.
On the other hand, there are people like me who started reading and writing xeroxed fanzines in high school, studied radical magazines of the early 20th century in college, and had to stop reading the newspaper in the late '90's because I didn't want to spend my time writing an indignant letter to the editor every week. I fully expect to keep blogging, pretty much in this format, until I die. It is a natural medium to me. Over the years, I've probably overestimated the extent to which it is natural for others.
So anyway, getting back to Ryan Bretag's post, he buys into the premise that blogging is primarily a conversational medium. If you believe this, you've made a fundamental misunderstanding of blogging. It is a publishing medium. If what you were looking for all along is conversation, you probably will move on to something that suits your needs better.
Beyond that, I could go on at length about why blogging and teaching aren't as good a fit as other topics, like politics or technology. Blogging on those subjects seems quite healthy. But I'll save that.