I have been here 12 years, and know people 15-18+ years, all in the same boat. I can be asked to leave the country tomorrow because I tried to switch jobs, my boss woke up on the wrong side of the bed or literally any or no other reason.
Why do you do it? I'm sorry if it sounds callous, I'm just curious really. I personally wouldn't be able to endure such a precarious and stressful situation.
You intend to leave the first 4 years.. Then someone applies for a green card on your behalf and you believe there's a path to permanence - and you see folks getting green cards all the time.. Then 5 years later you find out, because you were born in the wrong country, you get to wait 70 years instead of 1. But by then you have a wife, kids and a dog.
Then you kinda resign yourself to have to leaving someday but stay and make the TC you can while you can