Immigrants have always been a necessary evil, so to speak, the life blood of a failing corpus which found itself in need of cheap labor and quickly.
Immigrants as cheap labor are a repeat of the black slaves being 'a necessary evil' (your words) to pick cotton. And how did this work out? Been to Baltimore lately?
In fact, cheap labor is the reason why the machines capable of doing all that cheap labor were not made sooner. In that sense, cheap labor retards progress.
The question that you and others refuse to answer is: how does Japan manage without immigrants? They do have fast food joins and hotels, don't they? They grow things, too.
Japan is very expensive. I was there twice and didn't see one 'cheap' Somali cab driver. A country without immigrants. Holy crap!