Citizenship of all countries comes with some rules and expectations on the holder.

In some cases it is national service, others it is a requirement to vote, in the U.S. case it is to declare and pay taxes.

I would expect that most people like the idea of the option to live and work in the U.S. and keep their citizenship even if not residing there.

I think it is a difficult call to renounce citizenship but if the tax requirements are onerous on the individual they are least have the choice.