I don't think it is entirely wrong to be harsh on comments. What Tufte is trying to achieve is value on his site. Every comment that do not provide value is the

I don't think it is entirely wrong to be harsh on comments. What Tufte is trying to achieve is value on his site. Every comment that do not provide value is then removed. The alternative option can give a worse signal-to-noise ratio. Bad signal-to-noise ratio will make all intelligent beings with little time on hand go to other places, because wading through all the noise is too expensive. In that respect, it might be worth being harsh on comments to keep certain commentors on the site. I don't see it as censorship. You are free to make your own blog post condemning the view, start a comment-stream, use well-argued points, etcetera. In fact if the discussion is so vastly different it would probably be better served as a post of its own, laid out with good argumentation.