I dont think the blame can be appprtioned the the captain alone. For instance, why the co pilot out of the flightdeck so long? He's being hailed as some kind of God in some forums. Yet I believe a little of the blame could rest on him. There's also clearly cultural issues going on here too.
I believe according to the CM rules we can appeal the sentence.
In my opinion the sentence is harsh. Negligence yes. Gross negligence no.