One interesting line in that news item is "Indonesian transport minister threatens to sack those who cleared QZ8501 for take off when AirAsia was not permitted to fly on Sundays" - not that it has any relevance to why the accident happened.
Or maybe it has, assuming the passenger quota for SUB-SIN was correlated to all the other flights through the area and had something to do with potential safe AC density and separation in an habitually weather threatened airspace.