I agree with most of your points, but:

> So your forefathers did something great so you're entitled to untold riches?

Yes, the poster is entitled to the benefits of living in the country they were born in. Infinitely more so than foreigners are entitled to access to his country. A country has an obligation to its citizens, arguably more so to those who have sacrificed to allow it to exist, and none to outsiders who wish to join. Those outsiders' desire to join should be considered only insofar as they benefits the citizens of the country, and I think you've fairly illustrated where that can be the case.