I have a lot of sympathy for the article, though I agree it's not very focused. In my experience, "correlation does not imply causation" is mostly used as some sort of magical talisman in discussion, wheeled out by people who don't really understand it in the hope that it may do something.

I've been considering writing a discussion post on similar rhetorical talismans, but I'm not sure how on-topic it would end up being.