That's interesting. Someone who was born in country A and is a citizen of country B and decided to live in country C, no longer wants to be a citizen of B (which would be understandable for a lot of reasons, taxes being only one of many) still has to pay taxes as if he/she were actually using country B's tax-funded services.
Even worse: someone who was born in country B and lived his whole life outside of country B, still needs to file taxes and pay social security every year as if he was living in country B. That's my particular case.
Well... You may still use their diplomatic services, vote, and freely return to B without first asking for permission. But I agree that you should be billed accordingly to the expenses you actually generate and that the process should be as painless (and cheap for B's government) as possible - something like a fixed amount per citizen that could be waived if you declare you are too poor to pay it.
How much does a citizen cost to B's government?