I think a little quote from the GP explains a lot:
who take any available job and try to work their way up, but opportunities never appear.
You see, the thing about emigrants is that they are not satisfied by staying within the system they know, going for the steady plod up and hopeing that luck will land them with a big opportunity. The passive way never works unless you're born in the right family with the right connections.
Immigrants go out there and make their own way: they seek or maketheir own opportunities. After all, this is the kind of people that is willing to leave their own country, their family, friends and all that they know to go to a far away place where even things like unwriten social norms are different - starting your own company is a far easier endeavour.
The reason I know this is because I'm one of them and, not so long ago, after 3 countries and 7 years as a freelancer in IT I started my own Startup. I look around in the startup incubator where I'm based (Google Campus in London) and most people in there doing the same as me are foreigners too - in light of what it says in this NYTimes article, the abundance of foreigners now makes sense to me.
(PS: the GP's posture kinda reminds me of a friend of my who is an actrice - a profession with high unemployment - whose acting career goes nowhere preciselly because she keeps waiting for acting gigs rather than being out there promoting herself and looking hard for new opportunities)