The US is seen as a bit of a backwards country; poor medical, technologically poor (banking, internet), little paid time off/vacation, no free/cheap higher education, rampant gun violence/domestic terror - on top of that you risk loosing some pension and health benefits in your "home" country if you stay abroad for years.

Note that the point with a solid/free education system isn't that kids of rich SEs get free college - it's that society as a whole gets better education - and your kid's friends also have a future/access to education.