Just some constraints off the top of my head:
The legal system - it is not recommended that an 18 year old date a 16 year old because of wedged legalities and then the potential vindictive female's parents. This "age gap" judgment may continue somewhat into the college age by the individuals themselves and act as a barrier.
The education system - it was beat into our brains that you needed good grades to get into a good college, a good college education to secure a job and lifelong prosperity... LOOK. WHAT. HAPPENED. Some research and literature suggests the average person graduates in 6 years, not agreeing or disagreeing, but do some basic number crunching and use a "fertile" age range and females are 23-25 by the time they come out. Then you can factor in thousands -- if not hundreds of thousands -- of dollars in debt which takes at least another 3-5 years to resolve for both males and females.
The recession - all the kool aid we drank in the 90s and 2000s about the importance of getting into a good college turned out to be a double down on education. While education is fantastic and an unlimited good for our society, it has failed from a financial standpoint. Not for the faculty and staff doing studies of studies for a living but for the people who invested in it. The return on investment is "not good" for "many people". Civil engineers working at subway. Political scientists as hourly librarians. Computer programmers as grocery baggers. Why did they go to college again?
Technology - these smart phones and super gizmo computers are not doing us as many favors as we'd like to. Ever look around at a bar these days and see everyone beating down on their phones with their thumbs? Was that the case 20 years ago? The younger generations are depersonalized. Remember when it took guts to ask a girl to homecoming? There are probably guys that send out mass texts now doing exactly that. They dont learn emotion or how to articulate. The machine does it for them. **key point** Too much on screen time is a major problem for humanity. Also someone mentioned this warped sense of reality drawn from social media.
For instance, wheni open up my social media and it's new borns, new homes, picture esque dinners and gatherings, perfect families and hundreds of likes or more. Even for me who understands that these are in a sense braggarts and it is a pseudo sense of reality, it is hard to not feel pressure from that. If I dont have the potential for hundreds of likes in picture of my girlfriend and I, i probably wont post it. If I post it and we dont get the likes like her friend 'Jenny' and her BF get she'll second guess our relationship and so forth. She will long for that very validation to signify she has made it which is a very unnatural experience and too focused on social acceptance and popularity. Moms -- who are just as infantile and even worse -- have facebook too nowadays introducing yet another layer of pressure (i.e. why cant you have a boyfriend like Jenny or did you see Jenny's new post).
Combination of everything - the college kool aid, the college system itself, the recession, the technology...is it any wonder how or why these kids (including myself) felt entitled to a prosperous career? We did work hard. We trapezed backwards through every flaming hoop. Unfortunately, most that worked hard left hard working efforts in school and not in the job sector and marketplace. They gained only a less than satisfactory lesson of accomplishment. "Do all this work now and get a great job" and then the great job never came. We are simply over educating for too long, wearing young people down during their formative years and then not providing them the economic stability to prosper. Social media has deluded what happiness means and warped minds into thinking they arent good enough or arent holding up, 24/7 365 days per year.
So that's what I think.