In a cocooning period, the social world shrinks from including genetic strangers ("peers," "the community") to only the nuclear family, or a proto-nuclear family ("a couple").
A single little nuclear family cannot provide for all of a person's social needs, or even a good chunk of them. It places unnecessary stress on each family member, who is expected to fulfill too many roles within the family, leading to cabin fever and an incestuous vibe around the house. Now you know where Norman Bates came from.
Earlier posts (such as this one) have explored the effects of the child's total social world being the family. When your parents provide most of your social interaction, you wind up brattier because you don't get as much honest feedback as you would from genetically unbiased people AKA your peers and other adults in the community.
And it undermines the parents' authority when they make the family the extent of the social sphere. You can't be hanging out with your kid one moment and then order him around the next. Friends cannot boss each other around, and authority figures do not casually hang out with their subordinates. You can pick one role or the other, and helicopter parents have chosen to abandon their authority and act as substitutes for the kid's peers.
They'd rather die than let Outside Influences undo all of their tireless parenting. That would be like leaving your carefully worked clay sculpture right out on the sidewalk before it had a chance to harden. Might as well hand it over to the dogs as a chew toy. This blank slate mindset is one obvious reason why they don't want their kids to spend any time with their peers.
But I've noticed that it goes further than that, to include jealousy. When they think about their kid spending dinner at another family's house, they obsess over all of that quality time that the kid is lavishing on an outside social unit. Lousy ungrateful traitor!
Especially if he chose to go over there by himself, not as part of a parent-orchestrated "play date." The parent feels like they've been ditched by a fairweather friend, or like a jilted lover who's been stood up.
In the good old days, parents didn't feel jealous but joyous if their kid was invited over for dinner, a movie, a round of mini-golf, a sleepover, or whatever. "Great, my kid's making friends and becoming part of the larger community!" Their worst fear was that their kid would be a social loner, headed down the path of solitary vice (drugs, heavy metal music, cult membership, suicide).
Grown-ups back then viewed other grown-ups as their social circle, and expected their kids to interact mostly with their own age-mates. Peers and the community, rather than the family, was the primary social unit, so their kid spending time at another family's home was not a loss or a fragmentation but a gain, a solidification.
Aside from breaking apart the bonds of community, helicopter parents have also injected a creepy incestuous vibe into family social life. And you know what they say about a woman scorned. That only traps the children more tightly from the outside world.
The last time around, in the mid-to-late 1950s, the only way out for young people was to disobey their parents and hang out with each other in public against the parents' wishes. And it wasn't the end of the world.
Naturally with all those people out and about, mostly as potential targets, the crime rate began rising until just after folks started cocooning circa 1990. But we just have to take the good with the bad. The surest way to eliminate crime is to cut ourselves off from one another and hide away for good in private bunkers. The early '90s was as bad as crime got, and that wasn't the end of the world either.