But they won't.
I don't know what fantasy land the author and reviewer live in, but here in America in 2019, the world is a dangerous, knife-edged, and pitiless place where it's a constant fight of all against all. Anyone you meet, even immediate family members, is your enemy by default, and usually an ally at best. Everyone ruthlessly exploits everyone else to survive, everyone kills and dies by inches to eat tomorrow.
I've no idea where these people come from saying people love and support one another. Out here, others are either threats or exploitation targets, not partners.
Very good article nevertheless, helps to sort out adaptive things from maladaptive things.