It didn't say WHEN the woman became a Buddhist; for all we know, that may have been why they were 'estranged' from one another. And I don't remember reading ANYWHERE that they raised their son in ANY religion, which is why I think he gravitated to Islam and especially the Taliban. It is a very STRICT sect, and I may be armchair psychologizing here, but I think that's WHY he liked it; he needed the structure because it didn't sound like he'd had much growing up.
Well hey, look on the bright side, at least now you are thinking some. No way can you call a man a strict Catholic if he doesn't raise is son in the religion. Just no way. I agree that kids serious input of values will go looking for them elsewhere. Islam offers really serious values. You don't like them, but they are serious.
Islam is particularly suited to the desert, and it is in it's nature there highly mystical for those pre-disposed to such things. Take, for example, T. E. Lawrence. Don't accept the pulp junk the air heads on TV pump up about it. They don't know squat about any religion, why should they understand any religion?