Dogs and cats are far more dangerous to children than ball pythons. There's never been a recorded case of a ball python causing permanent injury or death to anyone, children or adults.
My sister has permanent scars on her face and chest from a friend's very trusted and "friendly" pet cat.
Life is full of little risks....we don't even think about them when considering a pet dog or cat...the risk that comes with them seems natural and easily accepted. The risks of injury from a ball python are almost nonexistent....just not so easily accepted, for whatever reason.