Take a stab in the dark.
More religion is not necessarily a good thing when the religion is Islam. Many examples & scripturally based causes for jihad are covered in this 5 minute clip. So are many questions as to why something so obvious manages to escape the attention of so many observers.
Jihad Watch director Robert Spencer discusses the case of Arman and Omar Ali, Muslim brothers from Texas who became devout in their observance of Islam and then joined the Islamic State (ISIS).