We definitely shouldn't care what he says; He's probably just begging for attention. But he is a US citizen. A quick search shows he became one in 2002.
Countries in the Americas are actually pretty unique in that most of them follow jus soli, where citizenship is granted just by being born in that country. The "old world" mostly uses jus sanguinis where citizenship is determined by family lineage, although some countries grant exceptions.
There's a lot to be said about the treatment of immigrants in various communities throughout many of these countries, but the issue you're raising here seems to be a consequence of a pretty decent policy.