It was for a time. It's not like that anymore, although it is trending that way again in many cities (homicides are up 50%+ in many American cities this year).
Although to be fair, a lot of the crime is in areas the average HN user wouldn't be in. Most people are not worried about getting carjacked or mugged during their commute and have no reason to be. The US is a big place and problems that affect certain parts of it are usually not present throughout the whole country.
Counterpoint: I lived in the North side of Chicago and worked downtown for a few years and I never heard a gunshot. Violence in Chicago is very localized in certain neighborhoods (West side and South side when I was there, not sure about now).
You can still see remnants of it, e.g. the Port Authority--aka the world's seediest bus terminal. But, as someone who lived in Manhattan for a summer in the mid-80s, it's hard to see things like the "Disneyfication" of the Times Square area as having too much of a downside.
Although to be fair, a lot of the crime is in areas the average HN user wouldn't be in. Most people are not worried about getting carjacked or mugged during their commute and have no reason to be. The US is a big place and problems that affect certain parts of it are usually not present throughout the whole country.