Both Justify and List make sense in context of their neighbors. All the other uses are by themselves and they don't mean "menu" they mean "drag from here". The icon is called a "drag handle".
I kind of agree for the "drag to reorder" in the stocks apps, but this doesn't work for Facebook and Bootstrap.
For Facebook, it doesn't work because the grip is not the in the correct direction. The grip is a skeuomorphism for real grips that go perpendicular to the movement you want to stop. Here you move your finger horizontally and the lines are horizontal too.
For Bootstrap, it doesn't work either because the button stays where it is, whereas the grip should follow your finger or mouse. (see for example, the grip on the notification center on iOS: http://iphoneism.com/wp-content/uploads/2011/06/notification...)
That being said, I think in both Bootstrap and Facebook, the icon represents a list: the list of things in the menu and the list of settings (or views) in Facebook. Even in the iOS stock app, I think it's probably a list too. It can be interpreted as a grip, but only in the Android version do the graphics imply it more strongly.
The lines are pretty recognizable as drag handles (in lists, on windows, etc), but to be honest I never dragged that icon in Facebook until you mentioned it. In a button, they do not look like drag handles. On the iOS keyboard, one thing that makes them instantly readable is their physicality (they're embossed), which communicates 'grip'. The grip concept goes back even further, to the classic Mac OS look.
As an anecdotal data point, when I hit "edit" in my phone favorites list on the iPhone, I always saw the "drag handle" as a little list, which I understood as a clumsy stand-in for "reorder this list." The "drag handle", as a representation of a little surface designed for friction so you can put a finger on it and drag it, never occurred to me as a possibility, though I understood it in other contexts. Apparently users can creatively make sense whatever they see even if the intended analogy falls flat.
I think the popularity of retina displays will result in a clarifying divergence of these homographs into different representations. A few years from now we will see the collision of these different meanings as an artifact of low-resolution graphics intended for low-resolution displays. But a few years beyond that, I think we will tire of subtle distinctions and decide that homographs are not any more difficult to deal with than subtle visual distinctions. This collision has not resulted in significant user confusion; in fact, it has taken an unusually observant person to point it out to the rest of us, who were happily using these interfaces without difficulty.
See, for example, the four little lines on the bottom right key on the iPad keyboard: http://ipadinsight.com/wp-content/uploads/2011/06/iPadKeyboa...
Or the three little lines in the bottom right corner (drag diagonally) of pre-Lion OSX (drag from any edge): http://www.cs.williams.edu/~freund/cs136-073/unix/window.jpg