I don't think we're too busy. I just believe most people today prefer to live in a world that is less formal than in previous generations.
Little children are taught to address adults on a first name basis. On the surface it may seem like a small thing but when children were expected to use Mr./Ms. it served as a buffer to distinguish how they talked with their peers VS how they spoke to adults.
Another example of change is we no longer view those in power in high esteem. Simply put we have seen too many scandals involving politicans, religious leaders, athletes, and entertainment figures.
Lastly as much as we needed equality of the sexes it has also led to the decline of some of the perks that came with chivalry.
"Old-fashioned manners" was a way of showing "respect" to someone. I still believe there are quite a few people in this world who are polite. It just seems sometimes that we may have to get out of own communities, cities, states, or country to witness them in action.
However if we keep our eyes and ears open in truth we'll see acts of kindness all around us from someone opening a door for a senior citizen, picking up something that was dropped by another person and returning it, waving at a driver of a car granting him/her permission to get in front of them as they enter into traffic from a parking lot...etc We tend to focus on what is wrong in the world more than we do with what is right.