The Messenger Muhammad (alayhis salaam) described the Kharijites as "Dogs of Hellfire" in what is authentically related from him through the companion Abu Umaamah al-Bahilee, and there is no doubt that Sayyid Qutb (see here, here, here, here and here) and those who followed him in making Takfir of nation states, societies, or the rulers of the Muslims upon other than the usool of Islam and calling for revolutions enter into these labels, descriptions and revilements which have come in the Sunnah which were made againsts the Khawaarij despite their apparent piety and exaggeration in fear - it was ignorance, sentiments and desires that led them astray.