It's the same thing with the Catholic Church. Widescale sexual abuse of young boys by priests occurred, but not because it's a cultural aspect of the Catholic Church. It's a disgusting corruption that somehow manifested itself by pedophiles that infiltrated the Church and abused their positions, just like in Afghanistan. So there's no lens of morality to view things with. What happened in both cases is that it's a crime that has grown due to widespread corruption. I'm sure you will find that a lot of money was stolen by the Afghani military as well, but theft is not cultural as well, that's corruption and abuse.
The same thing happened in the British government where a widespread sexual abuse ring was discovered recently. Is that also "cultural" aspect of British people? No, it's corruption and a heinous crime.