A general observation would be that in-group and out-group behaviour in teens and early stage adults is normal, but normalising the formalism of being in or out is a regressive tendency.
you may like it. Lots of people don't and it's their business because its about all of us in the end.
That said, Geraldo opening skull and bones vaults Doonesbury is a great cartoon sequence.
A better model might be "erasmus" -a European norm, which has led to strong bonds, without the hazing and drinking rituals.
When you have someone saying that everybody has a certain problem, the problem is usually them.