If those countries are a mess they come here, you don't want that so please pay them to go away, that's literally what they tell the common British taxpayer. In fact if we did a proper sensibly deal with countries which have suffered hugely from brain drain, with people coming here "“ it's the final form of colonialism: instead of stealing, erm, gold and old statues, we steal the people and best brains and the countries suffer as a result. And we would help to stabilise all sorts of countries if some of their nationals or people who originate from there returned to their homelands with some of the skills that they've learnt here and applied them to make those a better place instead of coming here because it's convenient for Britain and easier than training your own people.