I agree that both have a place. After all, it's in a blog that I was able to point to a better account of my ideas.
And note that Robert MacMillan's piece was an interview, not just reportage. It's far more common that a reporter gets only a few sentences of an interview into an article, and a blog lets you give the whole story. See for example my blog on Apple as Innovator, which started out as an email interview for the Baltimore Sun, but which I published as a blog after being disappointed with how little of the interview made it into the story. But note also that the Sun story was a good story -- my complaint had nothing to do with quality but only with the limits of word count. So blogging and professional reportage are great complements.