He wants a world that's free of constraints.
That's the simplistic model that has caused a chunk of the world's problems. As if property rights aren't themselves a sort of constraint, and as if speech cannot be damaging.
Freedom is anarchy without the law removing its rough edges. And the law is an instrument of autocracy without democracy to shape it. We have a framework by which we manage liberty because it works better than any other system we know.
Like many scientists, Musk is shallow on politics. And like many super-successful people, his ego has got the better of him. He's a sort of wooden, heroic-capitalist character in an Ayn Rand novel. With twitter as his political platform he can do immense damage.