Well, I'd imagine the worst is that they'd waste a lot of time doing something that doesn't exist and makes them look like complete retards to others. You want that for your kids? If no, then there's your answer.
Kid's becoming intrested in something? Oh No! Kids being looked at as strange or "retarded", why, that would never happen without a belief in PK! Thank goodness we have you here to save us from our own stupidity!