I agree 100% with the article and i think its just something that happens to adults, not all, but a fair slice of middle class people just become very smug, very conditioned by mainstream culture and very difficult to please.
A few trends that seem to occur. Often parents become narcissistic to everyone around them, simply because they are constantly in control and become a boss 24/7 to their kids, so they become that personality to everyone.
Other personalities are just very difficult to gauge.
Which is why i love it when i meet someone late 20s, early 30s who is still a bit silly, has empathy, is just nice and hasn't become all twisted and evil yet. They just stayed down to earth and nice and didn't turn to the dark side of narcissism or big ego and superficial.
If you worked in retail you can tell the nice people from the arrogant with little empathy, it's obvious.