[isoskeles]

Devil's advocating here, because I agree more with your sentiment:

That comment has sparked a larger subthread specifically about Twitter as a medium, rather than the content of the post. This specific subthread is so popular, it's near the top of the page every time I refresh this post. So we could say it stifles discussion, also because people are prone to voting up a comment like that despite the fact that it's not really relevant to the post.

[lultimouomo]

And that's why the [-] button is so awesome.