But this is utterly stupid:
"There is a subtle increase in complacency and a corresponding lowering of professionalism in many skilled people as they age, and as their experience, and "hours in the seat" increases."
You can speak by yourself or people that built their careers on a less than professional environment, on dated standards, bad training and such.
'Au contraire', as people age, the more they learn from mistakes, from stupid things like this one, on how expensive being casual or too relaxed can be on accomplishing our tasks.
The accident statistics aren't age related, but very linked to air safety culture and psychological/psychiatric factors.
No much different from road accidents.
There are many, many stories were the silver haired just saved the day. The reverse isn't true.