Common courtesy was never all that common, or it tended to accumulate at some places and not others. Some of the elder stuff (not in Japan, it's almost a religion there, whole different deal) comes from the segregation of the ages in the US, and its' less common to have older people around in a lot of areas. I don't see a lot of rude behavior outside of the ghetto where I work (and no one gets any respect there), most people seem polite and practice courtesy.
And it's not just old people - and nowhere near all of them - that are having more and more problems keeping pace. Things have speeded up, not just a little, but a lot, and plenty of people are not really planning to the best outcome. So while I never rush them, I will try to find another line.