A "proven assumption" is a linguistic contradiction. Furthermore your question is invalid as "not good" and "screw it up" are not objective criteria which one could prove or fail to prove.

But I must ask: have you ever seen A Government? That's a serious question. Look at any large Government around the world and look for any complex legislation that involves a relatively new business sector or financial instrument. Much of it is obviously terrible, or will turn out to be terrible, or is occasionally so terrible that it creates ripple effects which trigger financial crisis.

Australia launched a new economy-wide GST in 2000 which did many things, and one of them was a massive transformation of the cereal bar/museli bar/granola bar marketplace—changing recipes and picking new market winners—because Governments are terrible at writing legislation.