Tallsar - I completely endorse your last paragraph, of course, but to answer your (rhetorical?) questions:
With no specific reference to this accident, inadvertent entry to imc requires an immediate decision, either to turn away (ie re-route), make an emergency pull-up to MSA or possibly to manoeuvre out of the 'imc' if terrain etc allows.
Yes, CFIT will always be with us. AKA "What's that goat doing standing in that cloud"?
Back to this accident, I would assume that an experienced crew like this one would have been fully aware of para 2, and it remains UNKNOWN AND UN-PROVABLE why their flight path followed as it did.
Incidentally, may I assume that all the dissenters have given up trying to support the 'imc at waypoint change' mantra or do we still have some diehard W&D supporters? If we can establish that we can move a long way out of this swamp.