Sharp objects are usually of more concern than firearms, as they are much more commonly carried and easier to conceal. Anything from needles to box cutters to knives pose a much more immediate threat; In fact, in close quarters, knives are considered just as or more dangerous than firearms.

Also it's important to note that to legally carry a gun, one must have a CCW (carry concealed weapons) permit (at least in California), but people carry firearms illegally in pretty much every country.

Just like looking to anime for an accurate depiction of Japan, one can't expect Ally McBeal or even CSI to paint an accurate picture of America.