I lived in an "urban" area and I didn't have bars on my windows. I'm sure the chance of me being mugged was higher than a suburb, but that's more a function of population than anything else. It's still low enough that it's a negligible risk for me and my girlfriend. While I've certainly seen discarded needles in big cities, I've never come across them on the lawn of major parks and actually tend to find them in the more suburban areas of cities. Most big cities have at least some schools that are very good, even if some of them are sub par.