The issue of "design fault" was raised a few posts back. I might agree in terms of the maintainability of the jackscrew. Pulling a ladder or scaffold to reach the stab isn't exactly the easiest sometimes.
OTOH one failure over the decades doesn't exactly shout "bad design" when dozens of other operators had minimal issues with the jackscrew. The finger definitely seems to point to the operator in this case.
BTW, the accident occurred off Santa Barbara, past LAX on the way to SFO.