I don't understand why that "terrifies" you, Elon Musk is a historic visionary and the most successful Entrepeneur of modern times, so I don't see anyone better to advise the executive branch on the most effective ways of downsizing the federal government to fit our means. This is not optional, if we don't take drastic action this country will experience a default and all the horrible consequences that follow, incrementalist just will not work.
Will he succeed? that remains to be seen, he'll have a lot of resistance from entrenched interests fighting to keep the gravy train running but the fact that he's willing to put his intellect and ability to work tackling this enormous problem should be applauded by every citizen that cares about avoiding fiscal catastrophe and preserving individual liberty.