Well, rich people move to Belgium to pay (a lot) less tax (popular among Dutch and Americans for instance: you can go to mansion towns like Schilde and Braschaat and find only American and Dutch legal tax evading millionairs); so as with everywhere, you will need to force the rich to pay like everyone all over the world at which point the problem will already look different. Sure they might have worked for that money but paying less or no tax: how is that fair? Won't happen soon though.