Some adapt faster to a new cockpit than others, it's sometimes also a matter of self percetion ...
I find it however quite revealing that for their direct recruitment on new equipment, airlines make a marked distinction between conventional and glass cockpit experience. Now where do you think this might originate? Could it be statistics of failure or higher training needs? I do think so.
Considering that, it must come as no surprise what the NTSB found out. The remedy is training, which implies cost and time ... and those two seem to be the biggest hurdles in privat and commercial aviation.