It Is foolish and dishonest to accept that murder rape and plunder is to be considered in the same catagory as what genuinely religious people do.
King Abdullah says DAIISH terrorist scum are the enemy of Islam and that is to be translated for anyone too full of hate and bigotry to figure out that DAIISH terrorist scum are the enemy of religion in that case. They are not religious beings and nothing close to being religious at all. I'm not religious myself but I am very eager and able to respect all people who make religion part of their law abiding lives.
King Abdullah is not a binding religious authority. IS says they are Muslim. On what religious authority do you base your accusation of takfir against them? What cause elevates your authority above that of the Qur'an in regards to who is and is not Muslim?
“Surely your Lord knows best who strays from His path, and knows best who follows the guidance.” - an-Najm, 30