Yes, it kind of is a raw deal for immigrants. But it’s one of many things that suck for immigrants (look at the fees immigration attorneys charge). The exchange is that they typically get a 2-5x multiplier in earnings from their home country and consider it worth the risk.

It’s kind of like med school and residency. It really sucks and is difficult and is a “raw deal” yet everyone puts up with it because of the payout.