I think my explanation is fairly self-explanatory but to slightly elaborate:
A rule that cannot be enforced or that everyone does not voluntarily abide by is not a rule
Let’s say we have this ‘rule’ of ‘governance cycles’…what happens when someone makes a proposal ‘out of cycle’? You have no way to punish them, you have no way to prevent other people from supporting the proposal out of cycle–because the real rules are onchain, not whatever ‘rules about cycles’ we bureaucratically make up on these governance forums.