If you want to keep people on ILR/ Visas for 10-15 years without any safety nets in a country where literally everything, from the government to the private sector, was designed with the idea that people will have that safety net, then you should exempt them from paying taxes that go that Welfare pot so that they can get private insurance & savings to protect themselves and their families. They cannot contribute their money to a large welfare system that they are not going to benefit from. What kind of extractive system is that? When will the British Empire stop trying to squeeze every last bit it can from people and leave them high and dry? This is not even taking into account that the same people that you want to exclude make up the bulk of the Labour keeping that Welfare system running.