I guess it's always been a human urge to want to fit in. The sheer vastness of our own existence is, at times, too much to bear; to this end, we seek to at once limit and expand our knowledge of ourselves by putting ourselves into boxes.
Boxes to help us relate to the other people, to help us feel like we belong. Maslow certainly didn't realize the state of the internet-connected world would lead to an inversion of his beloved hierarchy - the blistering, smoldering need for us to belong, somewhere, anywhere, will make us do things beyond our wildest imaginations.
Will the slightest deviation from accepted, "normal" behavior make you an outcast? Are the boxes capable of carrying the same vastness that the very human mind couldn't? Because we'll all agree that humans vary infinitely at an infinite depth; no two people are exactly alike. In the face of all this vastness and uncertainty, having a sense of belonging is a soothing balm. Therein lies the benefit.
But what if the boxes aren't just that? What if they aren't containers, but enclosures? What if your box, in telling you what you are doing, begins to dictate what you are capable of doing? That's dangerous. The chasm of uncertainty that we look down on can't always be left unexplored - to move on, we must put on our harnesses and lower ourselves into the unknown. At times like this, boxes, in providing the comfort we so need, end up crippling us in the face of opportunity. The need to fit in is so strong that the slightest deviation from normal seems to be a giant yellow warning sign of things to break, and we avoid it, shutting off an unknowable number of opportunities.
We are each unique in our own right, and in that we are alike. By putting ourselves into boxes, not only do we prevent ourselves from experiencing life to the fullest, but actively poison our minds against the very idea.
Perhaps not being in a box is a box in itself - but like all boxes, it's made to be ripped to shreds in the process of self-discovery. We are beings of unfathomable variance and depth, and boxes are but poor microcosms of the universes we are meant to fill.
Boxes can be boxes, but should never be containers.