If it is a rule, it's a rule. There is no reason why every law could not be broken down into one page. Right now ( in the US) we have these massive changes that are encompassing thousands of new rules or modifications to existing rules.
This is a bad idea for the same reason that pushing massive untested changesets into an application would be a bad idea. Incremental, atomic changes that could be revoked is a much better practice on nearly every front (except for maintenance of the power of politicians)
That's why making the one page rule a rule of honour instead of a formal rule might help. Because you want people following the spirit of the rule instead of its letter.
This is a bad idea for the same reason that pushing massive untested changesets into an application would be a bad idea. Incremental, atomic changes that could be revoked is a much better practice on nearly every front (except for maintenance of the power of politicians)