If he'd actually continued to live in the US, I might have sympathy for this argument. But he's moved out. The US tax regime where expat US citizens still have to pay full tax to the US (except where there's a tax treaty that limits double taxation) is exceptionally harsh - almost no other countries do that.
> The US tax regime where expat US citizens still have to pay full tax to the US (except where there's a tax treaty that limits double taxation) is exceptionally harsh - almost no other countries do that.
This.
The US keeps taxing you after you leave. And for citizens, it is for life.
Why do you want citizenship? What do you think it gives you over having the Green Card. When I was going through the process to get my Green Card, my lawyer pretty plainly said that unless I really wanted to vote, getting citizenship gives you nothing but ads many liabilities.
The only real benefit I could have seen for myself was if I lived outside of the US for more than six months of the year from time to time.
I don't think it's entirely unreasonable. After all, you'd probably still expect the US Military to come to your aid if the shit hit the fan wherever you are abroad, right?