Because most of these stories are extremes. All my friends' pregnancies and major surgeries came with some hefty "residual" bills, but all got negotiated down or tossed. If you stand up to them they'll back off. About 80-90% of America has insurance that is "ok" and will keep you from going bankrupt. It's not as bad overall (big picture) as the anecdotes portray. Don't forget there are 340 million people in the USA (1% is still 3.4 million people, plenty of room there for stories to arise). It still really sucks and we need price controls and public option for insurance though. Also fear of the unknown, leaving your family behind, other countries in general don't like Americans unless you bring a few million dollars with you, other countries seem to have a very high barrier to foreigners working there, etc get in the way.