In the hypothetical scenario where an emigrant from the US is 100% determined to never return, and who also is confident in the long term stability of their new host nation - then the inconveniences of yearly tax paperwork might outweigh the benefits. However, I think that's more of a corner case than not as evidenced by the fact that the vast majority of emigrants choose to retain their US passport.
Renouncing American citizenship is extremely rare, as these figures show. The taxation is a paperwork hassle, but you need a very high income to actually owe anything -- for most, the higher tax rate in the new country offsets the American tax due.
If the Department of Homeland Security determines that the renunciation is motivated by tax avoidance purposes, the individual will be found inadmissible to the United States under Section 212(a)(10)(E) of the Immigration and Nationality Act (8 U.S.C. 1182(a)(10)(E)), as amended. https://travel.state.gov/content/travel/en/legal-considerati...
You don't officially have to give a reason to renounce, but consular officials might ask you verbally for your reasons. You are not required to give one though. You have the option to include a written statement, but I'm not sure why you'd ever want to take it (unless you really want to give them additional reasons to deny you entry).
[0] https://en.wikipedia.org/wiki/Reed_Amendment_(immigration)
That's not especially common.
Further details: https://www.americansabroad.org/us-taxes-abroad-for-dummies-...
(I'm not American, but none of several close friends in Europe with dual US/something-EU citizenship have given up their American citizenship.)
This is a big misunderstanding of US taxation. Every US citizen must file their taxes on income earned anywhere in the world, even if not earned in the US.
However, for most people, it is very unlikely to actually pay any additional tax to the US government.
https://www.irs.gov/individuals/international-taxpayers/u-s-...
"Your worldwide income is subject to U.S. income tax, regardless of where you reside."
But there's the foreign earned income exclusion:
https://www.irs.gov/individuals/international-taxpayers/fore...
If you live somewhere with higher taxes, you owe the US nothing. If you live somewhere with lower taxes, you owe only the difference.
US is also really fun for girls/partying if you have money.
30%+ of your income down the drain sucks a lot, but past a certain point in net worth it becomes somewhat attractive. Same reason people live in California even with the insane tax burden--it's really really freaking nice.
You have got to be visiting the wrong countries (North Korea?)
Literally anywhere I've been outside the US is a hell of a lot more fun for girls/partying than the US. And that's an understatement.