To be fair, the title was a (not-so-subtle) "twist" in that you thought it was going to tell you not to go to hackathons, but it flipped it by saying "Don't attend a hackathon... if you're just looking for devs to implement your ideas".

It was telling the "ideas people" to go away, not the devs to avoid them.

Isn't that what a hackathon is about? Maybe, "Don't work for free at a hackathon".

Writing code for one's own idea is play. Writing code for someone else's vision is work.