But the Parliametary draftsmen should word their statutes correctly according to how the Government wants the legislation to be
They do, but for a few catches:
1) they get it wrong
2) the first attempts at it cannot catch all combinations an permutations that life is capable of expressing
So begins a process of successive refinement until there is reached a point where it's not worth going to the effort of changing things again to catch the few outliers that remain
But the utopia you describe sounds dangerously close to BAS' desire that every law is clear and unambiguous and courts are not required because there is no room for interpretation. Fortunately, I think courts will always be required, and therein will always be pantomime and misdirection generating outcomes unintended by parliament