The part about why most suicide bombers are Muslims is based on faulty information. Specifically, that according to Islam, a person who commits a suicide bombing is considered a martyr. Not true at all. A person who commits suicide bombing is considered nothing but a murderer by Islam as well. Suicide bombers are merely "religiously" motivated by people seeking their own ends by twisting Islam and presenting a false picture of it to them. Why do the people believe them? Because they're uneducated and don't know Islam at all. Being a Pakistan Muslim, I've seen people in remote areas of Pakistan who can't even read the Quran, much less know what's written in it. They call themselves Muslim merely because they're parents called themselves Muslim, whose parent in turn called themselves Muslim. Such people are EXTREMELY easy to manipulate using false religious doctrines. Anyone showing up with a beard and shouting some Arabic gibberish can mislead them.
What the suicide bombers are doing is NOT a just cause. It's not even Jihad in the Islamic sense. Because Jihad has to be declared by the state. It cannot be declared by some individual. HTH.