I totally recognize my own friends in this. Americans have no clue how difficult it is to obtain a green card or a citizenship.
One of my friends was dating a girl from Asia, she was in the US under a work or student visa. She decided to attend a school in Europe for 2 years, their plan was to do the long distance thing for 2 years and then she would come back. I told him many times "Dude, if she leaves and gives up her visa she won't be able to come back". They ignored me, naively thinking that she would just get a new visa. 2 years later, she couldn't make it back to the US and stayed in Europe (or moved back to Asia, not sure).