> but you'd better design your systems to deal with it, rather than pretend that it's possible to stop it.
Ah, but see, no one cares what I think when designing systems. I'm just another programmer, you know?
The systems I get to design are things like: my career, my marriage, how I raise my kids.
And the sensible adaptations of my systems to unbounded immigration are: improve my lot, possibly at the expense of society's (making a bigger pie doesn't make sense if that simply attracts more pie eaters), prize relative status over absolute wealth (for the same reason), carry a gun, decrease my investment in society and retain options for moving abroad (same reason), and work hard to afford expensive real estate near "good schools" to send my children to elite colleges---elite you understand, not good enough, because with enough people, good enough, isn't.
And this is all antisocial behavior, and I don't really like it, and perhaps I will find a way to refrain from most of it and die in my bed in Oakland after ten years of philanthropy, surrounded by not only my multilingual grandchildren who, by dint of the virtues of hard work, collaboration, and generosity that I've taught, have managed to find their places in society, but also the neighborhood youths that I've mentored, Gran Torino style. That is the outcome I would be urged to pursue, and the one I personally find most fulfilling.
But: perhaps my neighbor Steve the auto mechanic is not so insufferably capable as I am, and feels betrayed by his country. What Steve feels is his due is loyalty, which means: discrimination. If loyalty to a company means that you stay there when you perhaps get a better offer from another, loyalty to a citizenry means that you favor its interests over some other body of people. And I do not get the sense that proponents of mass immigration favor the interests of the citizenry over migrants. I am happily ensconced at my well-paying tech job, so I will be OK---but what about Steve? What does he tell his kids when a Mexican (by pure chance---it could have been white, but this time, it wasn't) kid bullies them at school? Does he feel a moral obligation to consider the other child's interests? Is he likely to have a calm chat with the other child's parents?
What I am saying is: "You need to design your systems to deal with it" is equivalent to saying, "Fuck you," and while the moral and civilized response to "Fuck you" is "Have a nice day, sir," there are many who will not be able to afford that answer. Instead, they'll say "Fuck you." And (without the insulting meaning I ascribed to it earlier) you need to design your systems to deal with that.