To expand on your comment...
When any people, any society, become accustomed to something and can't recall to have been different it frightens them to think that it could have been or might yet be should they actually try it. I recall, 50 or more years ago, an American writing an article about his experience with British phone service and how glacially slow, backward, and consumer unfriendly it was. When he mentioned to Brits that America utilities were largely regulated businesses and better run, rather than government owned and run, the Brits he talked to were both surprised and almost disbelieving. The shock was not just that there could be far better service, but that such a thing as a regulated private business as operated as a telecommunications monopoly could exist - his hosts didn't see how a monopoly like telephone service could be anything other than a government owned operation with government employees.
The same psychology is at work in regards to foreign immigrant labor. My parents who grew up in the depression and long deceased grandparents remembered when it was different, as does any Okie or Arkie that came to California as farm labor. And, as I said, Canadians and Australians don't need illegals or Mexicans for their ag industry today. But like the rich Kuwaitis, or UAE, or Qatar, or Saudi Arabians who import poor Muslim Palestinians and Bangladeshi to do their menial labor; or like the plantation owners and farmers of the old south who depended on slaves, we have built an addition - a dependency - on low caste labor...unable to conceive of anything different.
It's a shame really, to be "too good" to mow one's own grass, or raise one's own children, or to nail drywall and paint siding. But I assure, there was a time ordinary white and black people did that without illegals - and frankly, we were better for it.
