I would guess it is more about creating and maintaining a demand for the products manufactured by the big names that are able to exert pressure on our politicians...
After all, it doesnt matter to a manufacturer/distributor where the cash comes from to purchase a shiny new or even second hand iPhone whether it comes from a government welfare check or from a wage check...
If you keep a high immigration rate, you sustain and grow demand from products and service across the community...
Of course the problem becomes that the net benefit to Australia is probably negative or at best zero from importing unskilled and illiterate immigrants except that you hope that their children will somehow get educated and fit in to the community.
