I know most have an agenda other than anyone prospering1, but what makes the “unrestricted immigration” crowd think anything good will come of that?
Like, even if their goal of throwing open the borders of the rich nations so that anyone can just show up no questions asked, what do they think this will achieve? Those wealthy nations will no longer be rich after their relatively high-trust societies are destroyed by Third World peasant cultural ethics and practices. Not to mention the actual rape gangs that inevitably seem to develop.
Suicidal empathy is the best explanation, as difficult as that is for me to understand. Of the ones who are being sincere, that is. And, thus, great civilizations will fall. They probably deserve it if they are not strong enough to preserve themselves.