I would add that many of my young staff are 'nones' because they can't believe any of the 'magic' stories and don't see where the Church is incorporating science in it's moral teachings.  They also didn't compartmentalize their religious training as a way to protect it from the influence of their professional or academic training.  Consequently if a given Church teaching conflicts with their professional understanding it's just one more reason to leave....and then of course, there is the whole hypocrisy thing.  Lots of that on display in all kinds of Christian denominations.