While that was a contributing factor in the AF case (I didn't look up the other one), it is far from the only one. Stating it like the FO training being, kind of, the only factor is over simplifying things a lot. Exactly what isn't happening with aviation incidents.
Have you read the AF447 report? The FO lacked basic airmanship skills, such as not stalling own plane and not knowing pushing the nose down to increase airspeed.... he would have failed PPL licence in a Cessna.
Sure, it was not the only factor, but it was one of the decisive factors.
