Like any fashionable word, "growth hack" is being assigned to all sorts of things that it wasn't meant to mean. This article attacks those other things, and not the core of what 'growth hacking' means.

A code hacker is doing things creatively and differently and coming up with a unique way to accomplish something that is difficult to accomplish following standard protocols like 'coder' would. A growth hacker is the same thing -- but for marketing and/or sales. By definition, once someone else shows the way, it's no longer hacking to do it; but the first one to do it, was a hacker.

I would argue that airBnb's cross-posting was hacking. The first person to some up with "give away the razor and charge for the blades" was a growth hacker even though that term didn't exist for another 100 years. Plain and simple, new and innovative ways to build brand awareness or increase sales is growth hacking.

Call it marketing hacking if it makes you feel better.

Edit: to add to my point: why use the term hacker at all if growth hacker is BS term for a certain kind of marketer, isn't 'hacker' a BS term for a certain kind of technologist? /rant