> The paperwork really isn't hard.
Yes, it is. Many of my friends are business owners, most of them have some international business. I've been in touch with a variety of tax professionals in different countries through the years.
In the last 10 years or so, I've seen more than one business or partnership outside the US state in its charter that "shareholder may not be a US tax payer, and may not sell his shares to one, and will sell his shares to someone who is not if he becomes one", because of how complicated it makes things.
If you think US paperwork is sane or is not hard, it is probably because you did not have enough exposure to it, or alternatively, not had exposure to a saner system.
Objectively: US Federal Tax code is >71,000 pages (as of 2009 when I checked - probably longer now). And it applies to every american. NYS tax code is some 15,000 more pages; if you are doing significant business in NYS, that's about 10 times as many details to be aware of than in any other country that I'm aware of.