I've explained here how hard it is here: https://news.ycombinator.com/item?id=12169640 (The U.S. is quite hostile to employment-based immigration, and probably among the hardest countries to move to for a non-family non-refugee immigrant.)
Also: have noticed the sheer amount of sickening hatred of immigrants in this thread? These entitled pricks think that they're the only ones deserving of an opportunity to live and work in the US (because they were "born here"), and they think everyone else should be kept out. It continues to amaze me how much contempt and hatred there is for immigrants, here on HN.