It is fairly recently that we have been advised to not just look at this or that unserviceable item one can operate with but also the interaction of various unserviceablities. Used to be you just looked for an item in the MEL and if it was there you were good to go. Now you are supposed to stop and think about the implications of coupled unserviceabilities, with updated MELs showing you how to do that.
If true, there has been a collective or unconcious downgrading of training... isn't a 'What if?' thinking process, instilled at about day one?
.. and then reinforced at every step thereafter?