I imagine recognition of its function is not static with time. 5 years ago it was probably less recognizable than it is today, and will likely be more recognizable tomorrow than it is today. Just like the periodically controversial floppy icon, of which I'm not a great fan; after many years of consistent use, most everyone recognizes it even though a good portion of the population have never seen a floppy disk in their lifetimes, much less have a clue what a floppy disk has anything to do with saving something. So the floppy icon continues to get used despite all that.
Love it or hate it, the practical value of the functionality underlying the use of the hamburger icon seems to be consistently overwhelming the aversion to it. Even the strict Microsoft Metro designers who swore against its use in the Metro guidelines have given into it for Windows 10. That said, I still think it requires care (and good guidelines) to keep it from becoming a UI dumping ground for application commands/actions.