Lawyers are paid to advance their employer's interests, not to achieve correctness. If one wrote up a contract that was so full of shit that the entire thing got tossed they would indeed get poor marks(this is why contracts usually insist on 'severability', so that any sections determined to be bullshit shall have no effect on the remaining sections). As long as they can avoid that, though, any advantage that they can derive by inserting scary-but-groundless language is pure gravy. If somebody doesn't know that it is baseless, or can't risk fighting about it, you get compliance without even needing the law on your side. If they do, well, it's just a severable clause, so no harm done.
It's an ugly sort of business; but pragmatic.