[kbenson]

I think it's a bit more nuanced that that, since he's also talking about placement of points and descriptive sentences and how it turns into a type of table of contents, which is a bit of both content and presentation in my opinion, but I could see how you might differ on that point. To me, data presentation and making it palatable to those intended to consume it is important, and not easily teased apart from the data itself when viewed with respect to communication.

For what it's worth, if you look at the source of the page, you can see how he actually does seem to care about line length with respect to legibility for himself, it just doesn't seem to extend to something he cares about with respect to his readers.