I'm interested to hear why you think comments are evil.
Would there be any way to make that discussion-like structure accept input from anonymous, infrequent, or lazy users? Setting up a blog just to reply might leave out some decent responses.
They're second-class outlets. A blog author can say whatever they want; their posts are first-class elements in Google's corpus; the medium encourages stand-alone writing instead of meaningless squibs.
The original vision of the "blogosphere" rejected comments. "Write a blog post, instead." Here's an old, well-known example:
The problem right now is that the affordances favor comments over posts. The first step is to adjust them; it just so happens that by making a threaded blog-group reader, you're also providing a lot of value to people who don't care that comments are evil, but do find it hard to follow 10 different blogs talking about the same thing.
There's enough structure in blogs (blogrolls, tags, date, author, backlinks) --- especially if you mine comments --- to do take a stab at this.