Up until the DAO hack (that you're referring to) "code is law" was commonly believed. That is until the Ethereum Core developers were massively affected by the

Up until the DAO hack (that you're referring to) "code is law" was commonly believed. That is until the Ethereum Core developers were massively affected by the hack and decided on an unprecedented rules rewrite to address the hack. (Which they haven't considered ever since, despite other hacks of the same type.)