Do you have anything you can cite that supports your point about this being a back channel immigration method?
I live in a city that has a huge number Chinese students, who I regularly see coming and going from the campuses. Not all top universities, either. It does seem to me like these foreign student communities can be overly insular but I've never seen any evidence that they're illegally overstaying at any scale. As they generally come from wealthy backgrounds and societies that heavily emphasise family values, I am skeptical that they'd get higher quality of life in the UK than their home countries.
I live in a city that has a huge number Chinese students, who I regularly see coming and going from the campuses. Not all top universities, either. It does seem to me like these foreign student communities can be overly insular but I've never seen any evidence that they're illegally overstaying at any scale. As they generally come from wealthy backgrounds and societies that heavily emphasise family values, I am skeptical that they'd get higher quality of life in the UK than their home countries.