“Call-to-action button”, the big button/link thing (which I never click on) that usually has “Learn more” beside it (which I do click on).

If not knowing what a CTA is is what confused you, then no, it’s not bad design, just bad targeting—you’re not in the target audience for this article right now. Not that you couldn’t be or that you wouldn’t benefit from knowing what it says, but it does require a certain (if minimal) amount of web marketing context to understand.

(That said, I didn’t find the article particularly insightful, but that’s because I don’t much care for or about the goals it concerns—a different way of being out of the target audience.)

CTA is "Call to Action", basically something to incentivise or get the user to do something on the website (usually register, click something, buy something...). Hope that helps!

Call to action. The thing you are convincing the user to do next. Click a button to sign up for a trial, subscribe to a newsletter, etc.

Call to action