The way I read it was: The hamburger menu hides crucial functionality behind an utterly nondescript icon, so people end up not using the functionality and making inefficient use of the application/website. Or they just bail out early when it seems like there is nothing left to do. The discoverability is horrible so most users will never use it.
It probably isn't helped by the superflat UIs that are the current fad that make it impossible to tell what elements are active or what they do.
It's the kind of thing that makes sense on phones because the screen space is so precious (although with modern phones this is becoming less and less true), but only because you're willing to trade off some usability for getting more content on the screen. For a desktop site or application where you are not space constrained it is just bad design.
It probably isn't helped by the superflat UIs that are the current fad that make it impossible to tell what elements are active or what they do.
It's the kind of thing that makes sense on phones because the screen space is so precious (although with modern phones this is becoming less and less true), but only because you're willing to trade off some usability for getting more content on the screen. For a desktop site or application where you are not space constrained it is just bad design.