If I live and work completely in a foreign country why would I ever pay US income tax under any circumstances at all? The US is one of two countries on this planet that expect people who's only tie is being a citizen (perhaps never having set foot there and not speaking the language) to file income tax and potentially pay a portion of their income.

Even worse, the US expects you to file with them the way you file in your country of residence. File join in the country you live in? You're expected to file joint with the US then. Which means your foreign spouse who has no ties to the US of any kind (outside of being married to a citizen) will potentially have to pay US tax on their income.

And worst of all, the tax is mostly an annoyance. The true problem is that you have to report every account you have signing power over. That includes pension fund. That includes your companies bank accounts that you manage (which is why an American will never hold such a position in e.g. Switzerland). Lots of banks also won't take Americans on as customers. They don't get enough to warrant dealing with US bureaucracy to report information on these accounts.

>You can always renounce your US citizenship

Which is what many people are doing. The US is one of the few nations on earth that people give up citizenship from.