Your principle that all matters must be referred to a Hukm, is a thanni principle, and not accepted by the majority of scholars who restrict this to the Ibadat only.
Most saw political systems as a Madaniya (which they are). This view is held explicitly by ibn taymiyyah, and Imran Ahsan Khan Niyazee (translator of Bidayat al-Mujtahid) in his book Theories of Islamic Jurisprudence.
So your assertion: they don't even refer to Qur'an and Sunnah...becomes as irrelevent as it would be when devising a management system for a hospital. Because you must accept this as a valid opinion and thus you must not call it Kufr.