Guest workers are not immigrants - they are sojourners who fill needs in the labor market. Immigrant is defined as someone who permanently settles in a new area/country. There is a lot the West could learn from East Asian immigration policy.
You do know most of the Turks in Germany came in a guest worker program?
Anyway, the big problem with this solution is you end up (in the extreme end) with nightmare states like the Gulf, where a pampered elite sit above an army of disenfranchised and abused workers