Mostly the problem is a) you still need to file taxes, which is complicated even further by being overseas, and b) the US imposes substantial reporting requirements on any foreign bank which serviees its citizens, which leads to a lot of banks simply refusing service to them. When people are willing to spend $2000 (it may be small to those making over $105k, but most people renouncing their US citizenship after moving overseas are not making that much) and give up their citizenship over something which is basically just paperwork, it's got to be pretty bad.