The root cause is not human factors, unless you consider Boeing engineering screw ups to be human factors.
The root cause is Boeing Engineering gave MCAS lots of control authority and unlimited applications of this authority, and tied its activation to a electro-mechanical sensor with some pretty obvious and well known failure modes, yet never did any range checking in software to detect any of these well known failure modes, and never did any end to end testing to show these failure modes had benign outcomes because they do not. The fix was the one Boeing was close to releasing last April when the 2nd crash happened: fix all these glaring issues in MCAS. Let it have its one push to smooth the corner in the flight envelope, pass the certification test, move on.
The pilot community seems to be happy to fixate on "if I only had information X I would have sorted it out". Sure, but the better idea is to do as much as possible to make sure you don't need to rely on the pilot sorting it out. Fix the damn code so the plane won't keep pointing its nose at the ground repeatedly the minute the flaps go up. Sure, also, tell the pilots about the "feature" and how to deal with it, but start by not producing such a dangerous product.
I think Boeing is happy to keep the discussion focused on human factors because as the name says they are human factors and are thus subjective rather than objective. It's a lot better outcome from a liability point of view than focusing on how Boeing Engineering produced such a deeply flawed product.