On the other hand, it is possible to change it with very little loss of revenue to the US because this taxation raises very little money in practice. Because of the 97.6k income exemption, as well as double taxation tax credits, the only real thing it does is create mountains of expensive paperwork for expats (as well as the IRS). Think along the lines of paying $5k to a specialty accountant to prove that your US tax bill is zero, every year.
The other part of your comment about this affecting only a small fraction of people is inaccurate. It affects all US expats - currently several million (6.32m is the last number I've seen). The only criterion for being affected is US citizenship. Foreign citizenship is irrelevant. You will be taxed in most foreign countries if you are resident there, regardless of your citizenship - and then taxed again by the US on the basis of your US citizenship.