Until a few months ago I was on the 6th floor of an office building. There was my office, which was a diverse company (minority woman owned, lots of black, white, hispanic, Asian, etc). Then next to us was a .NET shop. All they do is .NET software for the government. ALL Indian/Pakistani. They had one white guy working for them, and he and I talked on the elevator. He said that the only reason he was hired was because they couldn't find an Indian guy that knew his particular specialty. 2 weeks later I saw him on the street corner, and they had fired him and replaced him with an Indian guy. We shared a floor with this company for years, and they wouldn't even talk to any of the non Urdu/Hindi speaking people in my company.

This is the part where you say that I don't have all the information, and maybe he was a terrible worker. That's also the part where I say that you likely don't have the full picture of the "company club" either. The cultural divide can be huge. My former coworker grew up in Punjab. He was very apprehensive when he tagged along with me on a roadtrip (he loved football) and my wife wanted to drive. He told me "the women in my family don't drive." This is the kind of stuff that makes it hard to get into the "company club."