Sorry to hear you're experiencing such a lack of help and aid from your fellow humans, C.  Around here, we still help each other.  I live in a very politically Republican/Tea Party-ish county, and we still help each other.  There is a section of the local paper in which people make public declarations of thanks for kindnesses shown by others: lost pocketbooks turned in, help changing tires on the highway, food and help brought during illnesses, etc.

In the past, I can't tell you how many days a year we would spend helping each other's building projects, and it's true we can't do that as much now since we all need to work more (if we can) to keep our heads above water, but in general we do help each other.  The only downhill pattern I see often is the more general rudeness and selfishness of children.

What happened to us ?

The easy answer is the invention of affordable air travel.

People move a lot more and but can still easily visit nuclear family that lives far away.

Therefore, they do not need to create substitute family in those who live near them, and among those who live near them, they have the choice of only making friends with those who they really find compatible. You were no longer stuck with being nice to people you didn't really like only because they were your neighbors.

But I think it is more complex than that and I do not think your experience is or ever was the standard everywhere for everyone.

I do strongly believe that it is not anything new, it is a consequence of big crowded cosmopolitan communities where new people are always coming in and others are always leaving. I don't think what you think of as the "good old days" ever existed much in many dense urban situations, whether Rome, Constantinople, Peking or Paris. In that case, since personal space is lacking, privacy is top on the list in creating livable communities, a bit of privacy trumps helping each other. The ultimate downside of was exemplified by the famous Kitty Genovese story. What's considered a good neighbor is different--someone who respects the privacy of everyone else.

The pioneers who helped each other with barn raising had plenty of personal space and fences to return to after that neighbor's barn was raised. The immigrants living squeezed on top of each other in tenements on New York's lower East side most of all wanted to get out and get some more personal space, even if that meant having to pay someone to babysit and help with big chores and not having others around so close to rely on in crises.

Furthermore, the growth of the nuclear family, away from extended family and reliance on neighbors, was actually a dream fulfilled by FDR's New Deal et. al. Social Security meant nobody had to have retired Mom and/or Dad living with them any more. The GI Bill meant the son and his wife could escape living with and like his parents. The FHA and places like Levittown meant each little new family could have their own little home and piece of land and not have to live on the family farm. Etc.

I'm a boomer who grew up on several blocks of poorly maintained two-story rental flats mostly filled with young large working class families who could not afford a down payment on a house. (My parents could not afford that down payment until I was a teenager.) Us large crowd of kids ran free and wild among the untrimmed and unfenced yards and yes, everyone knew whose kids were whose and many watched what we were up to. At the same time, in summer, some moms shoved the kids out of the little crowded apartments in the morning and told them don't dare come back until night fall, because they couldn't stand all but the babies underfoot in a small 3-bedroom flat. Overall, my memory is that they would help each other if they needed a cup of sugar or a ride to work because the car broke down, but mostly what they all dreamed of was to have a place and the money not to have to require depending upon such neighborly assistance. An offer of hand-me-down clothes from one family to another would be considered an insult or at minimum a great shame if your situation was so bad that you had to accept them. The only barn raising type project I remember is my father and the man downstairs leveling the path by the side of the house and putting gravel down because the landlord was too cheap to pave it and their wives agreed the tracked-in dirt was driving them crazy.

And then there is another, contrary American narrative to yours out there that I know from personal experience.  My mother's family was 7 siblings raised by immigrant parents on a small farm on the outskirts of the city maintained by them and their mother in the Depression years while their father worked full time in a foundry, and did the farming on weekends and summer nights. The farm was to have their own food and other things like feather pillows, and have leftover to sell at the farmer's market. As each got married and started their own families, the ethos I got from all of them was take care of yourself financially and for similar needs, because no one else is going to do it. On the other hand, for health crises and emotional support and celebrations of milestones like weddings or deaths, they were very close, all there for each other like no one else. (My surviving aunts are still calling me weekly several years after the death of my mother, their sister. It's like they feel they must offer a replacement for her. They never pry, though, they just offer an ear.)

Their parents gave them nothing financial beyond allowing them to finish high school, and they expected it from no one, instead they were raised as if they were expected to prove the value of their existence to their parents. Also, once married, they were not asked for help back on the farm. Not a one of them ever loaned money to any other, nor helped with financial problems or things like a broken down car, they were taught to be self-reliant in situations like that, not depend on others, even their siblings, it was like a taboo thing to interfere with each other's nuclear family finances or to expect help from their parents or to expect services like babysitting from each other, they just wouldn't do that to each other much less neighbors.

Finally, one part of your story really struck me immediately as contrary to my own experience--this:

My father sometimes counsel parents that he knew and their kids. Like the time our milkman got all upset because his son did not want to continue the dairy farm. He wanted to be an engineer. So my father went over and talked to both of them and helped our milk man realize that maybe being and engineer was best for his son.

Neither of my parents would never ever do this; they would consider it being a nosy interfering busybody. They would really resent it if someone did the same to them. I even recall my mother complaining about the visit from a public health nurse after the birth of own of my brothers; she hated the idea of someone checking on the way she was raising her children, it was a violation of her privacy. My mother was a very social type person with high emotional IQ type, the kind that people liked to tell their problems to. But if your milkman's son came to her with his tale of woe about his father, she would listen and console and offer suggestions, and she would talk to my father about it and they would say it is very sad, but I can't imagine they would ever consider going to talk to his father about it, never, that would be taboo to them. And she would probably become a life long friend of the milkman's son, but she would never consider trying to solve his problems for him by becoming an involved negotiator.

Now that I look back on it, inspired by your own memories, I think almost all the families in my crowded childhood neighborhood operated on that principle, not to involve yourself in another family's business. Seems to me like it was an essential way they survived getting along with each other in a tense crowded neighborhood, For example, it was quite clear to us kids that there was a lot of horrible fights among couples about money but that that was something other grownups pretended in public was not happening. You could easily hear it all through thin walls and across the yards but you did not admit you heard it. Also that if someone got "laid off," it was something you whispered about and you pretended that the person still had the same money as before and you did not offer them help like they were poor or something, because that would be adding insult to injury.

http://www.booktv.org/Program/11850/Higher+Education+How+Colleges+are+Wa...