of course it makes sense.
If not , then where do you figure their salaries are coming from?
It's the same as a Tefl teacher in Thailand who sends most of his money back to the UK. His wages come from Thailand but so what if he pays some tax - overall the money is still LEAVING the country , thus taking food from the mouths of the peasants of Isan or some other such place. Same with the Eastern European mob - they are draining the resources of the UK and thus creating poverty for certain sections of the native British population.