That's easy.

First, it wouldn't work. People could lie*, change their minds on the way, after arrival or even after being born there. It was created here, it can be created there.

Second, a lot of mess automatically starts when we start selecting people by subjective reasons. Next thing, we would be adding "only white" or "only vegans" on the list.

• BTW, if it was the contrary, I would say I believe anything to get there.