That's only a good argument if you think they're bound to be a detriment in those "demands", or that basic dignity is too much to ask for hard labor in return f

That's only a good argument if you think they're bound to be a detriment in those "demands", or that basic dignity is too much to ask for hard labor in return for crap wages and no job security. Putting that aside even if you do accept the premise that people working and living in your country are a risk rather than an opportunity, it's a poor argument in favor of something that's necessitated by demographic change in the West (and places like Japan).