[fennecfoxen]

Because he already knew a guy, and he knew the guy was good, and he wanted to work with that guy. And "why did he have to hire someone from abroad" is a question that makes no more sense than "why should he have to hire someone local?"

[jeffsco]

The title says a team, suggesting that you can't build any team at all in US. But the evidence presented shows that he couldn't build a specific team: there exists a team he couldn't build in US.

[fennecfoxen]

This nitpicking is 100% accurate, but its relevance to the underlying immigration and employment policies involved is far more limited.