Self-inflicted? Yes. Problem? There is where you'll get lots of disagreement. The American Dream of a single-family house on its own lot is still very, very compelling for the majority of Americans. Many - I'd say a clear majority of - Americans want no part of a European-style rabbit warren, no matter how much our betters in the Northeast tell us it would be good for us.
We build out because we can, and because that's what we want. Yes, we know that's not conducive to mass transit, and we don't care. Europeans telling us we're doing it wrong get very, very tiresome.