It puts the lie to the "social contract" / "you agreed to be taxed because you haven't left" argument. You must ask permission to renounce your citizenship, an

It puts the lie to the "social contract" / "you agreed to be taxed because you haven't left" argument. You must ask permission to renounce your citizenship, and the government can deny your request, meaning you can't just leave. Then they charge you lots of money to leave, as you've explained.