1) Maintainability. JS is probably easier to grok in some circumstances, ie. you don't have to send new devs to a blog post to explain the CSS on your project.

2) Cost/benefit analysis of dev time, ie. you could do X (where X is some minor display that 1% of your users see) in pure CSS in 12 hours, or do the same in 30 min of JS.

3) Cost/benefit analysis of page size, ie. you can do in 4 lines of JS what would take 400 lines of CSS. Sometimes a few lines of jQuery obviates several hundred lines of CSS (between the media queries, browser-specific overrides, and so forth).

The interesting question the article should address was why the CSS solution was a better choice than the JS solution. I have a gut feeling the answer is way better than "we just wanted CSS only for purity's sake", and personally I'm interested in knowing what that answer is!