Nemrytter, a rather thorough analysis of the g-data from the FDR shows that no significant turbulence was encountered that would have hampered handling. They DID in fact encounter the icing problem, and if we do a very tight root cause analysis, we discover that without iced-up pitot tubes NONE of the rest follows.
The point a lot of people have made, pilots and others, is that UAS from frozen up pitots is a known malfunction for which there are some effective procedures. Likewise, if the FD goes wrong, or if UAS is the general problem, you turn the FD's off and take some other concrete actions, work through the procedures step-by-step, and get yourself back into the flying condition you desire.
Also of note, the data show that the UAS itself was intermittent, which to me means that the pitot's being rendered INOP sort of cleared itself up, but apparently not all at once. Trouble is, that wasn't necessarily obvious to the pilots, but a UAS procedure was available to deal with the fact that the airspeed input was acting up.
I appreciate your point on Wx avoidance, and also Robert's resetting the radar to a more suitable mode, which I concur let to the (late?) heading correction made (12 deg IIRC) to at least partly avoid what he diagnosed as Wx he'd rather not hit.
That leaves the crew with a malfunction which, had it been handled one way, we'd never have known about unless it was added to the other 36 UAS events that have been discussed at some length on the Tech Log forums.
The response instead included a possible misdiagnosis, and what appears to have been a low-alt tailored response to a high alt UAS event ... and it all ended in tears.
(Points on training, recency, and currency apply here in the human factors facets of this event).
It isn't as simple as Wx penetration being the cause.
There was still plenty of room NOT to end in tears, even with entering a bit of rougher weather than they intended to.
To make a rough analogy of a different way to die while hauling pax from place to place ...
I can make a turn in the wrong direction in bad weather near an airport. (perhaps on the way into Islamabad in rainy weather somewhat recently???)
If I notice my mistake (or hear from ATC that I am off course?) and make the proper correction to that error, I don't hit the mountain. If I instead keep my error in, and then do something that isn't correcting my heading error, I hit the mountain and it ends in tears.
The Wx didn't cause that, but poor Wx contributed to it -- right?