That's true when the risks outweigh the benefits, but it's not always true otherwise: we vaccinate everyone against smallpox to -keep- it rare! Unfortunately,

That's true when the risks outweigh the benefits, but it's not always true otherwise: we vaccinate everyone against smallpox to -keep- it rare! Unfortunately, the cost of removing this sort of security theater as a deterrent is invisible and hypothetical, whereas the benefits are obvious.