If the strata manager means the by-law wasn’t properly formulated, then that’s an issue you have to take up with the lawyer who wrote it. If the by-law contravenes another law and is therefore invalid, then that should be taken up with the lawyer who wrote it too. But if the SM is just being cynical about by-laws in general and difficulties in enforcing them, he or she needs to step up and offer more constructive help than a blanket disparagement.