Quote: "With a net worth of $134.7B, Musk recently surpassed Bill Gates as the second-richest person in the world, and he's on track to earn more than $50 billion in stock options. If he remained in California, he’d be facing income taxes on the profits when he exercises them. In Texas, there is no income tax. "
Rest is blah blah, this right there is the real reason for such a move. Can't blame the man either, I'll do the same in his shoes.