It's pretty easy to imagine a minority of administrators on a space habitat decide they'll take some critical system hostage unless they get a bigger share of whatever they want because they think (perhaps legitimately) they've been the victim of some injustice... overplay their hand, critical system fails despite nobody actually intending it, millions of people in the habitat die. Or a million other ways for disaster to happen because of human reasons, not engineering ones.
Here on earth, even when societies devolve into civil war and massacre (e.g. Syria the past few years), at least they don't destroy the earth along with it. But with a space habitat, even a partial breakdown of order easily means everybody can just die.
So let me be clearer: I wouldn't just "like" to see us manage Earth better first. My point is that this may very likely actually prevent space habitats from being viable at all. "Accepting that this trend will continue" doesn't mean we'll make space habitats regardless -- it means accepting space habitats might not ever be thing (no matter how possible the engineering is), unless it ever happens that we first make enough massive progress in our forms of political organization and cooperation as well.