“Open borders” is a religious inclination and declaration, no different than asserting that the eucharist is in fact the body of Christ. That some people really believe in the open borders scam doesn’t matter. Some people sincerely believe in transubstantiation, too.

And for the same reasons. It makes the proclaimers of the absurd idea feel bliss and elation and moral superiority. They expect others to bow before their moral rectitude and probity, and are confused when others do not.

There are other reasons, too, but the religious one is a huge one.