Well. Duh. The US PERM process is a nightmare. And it's not just the requirements and regional quotas. It's also the complete opacity of the process, with the USCIS taking _years_ to process straightforward applications in some cases.
No wonder people just give up and leave.
Dude, seriously. I'm a citizen and work in a lab, and I have a world expert in my lab... One of maybe 5 in the world, Canadian... And the difficulty for him to stay is insane.
If you asked any American how hard he should have it, they'd probably expect he just needed to fill out a form, pay $150, and wait 1-2 years.