Why can't Brits obtain a green card?

All people are elgible to apply for a Green Card. However there are different ways and different programs to get one,. Some of the more charitable programs exclude Great Britain and its common wealth countries and territories. I dont know why for sure, but I think its because your country isnt a crap hole so they figure you can wait a little longer or pay a little more to get one. Unlike people from 3rd world countries who are desperate for a new life and cant afford to wait or pay.