As long as he didn't broken any law, and he didn't regret what he did, why someone would say he did anything wrong?

You may think, he earn his money in the US soil and he should contribute back to the US people. Morally correct. However, if that means he have to fund the US government by paying tax and portion of that money eventually used for launching a war in the middle east, I also think legally avoiding tax to the government is morally correct.