To be entirely fair to America, I don't think the sheer size of your country helps. When people think "Ghetto" in the UK, they think of areas that you can drive through in less than 10 minutes. Don't get me wrong, we have some really terrible areas (The worst local to me had a spate of gangsters chasing each other on motorcycles shooting each other. At one point it was declared an official no go zone to Police without an armed escort), but they're absolutely tiny in comparison.
So when we see huge parts of huge cities that are just, well, terrible, it just looks absolutely insane to us