Playing devil's advocate...........
Mercurydancer = safety-police...It's his JOB to decide things are unsafe and therefore maintain a nice number in enforcement employment....I'd be interested to know where his god-like superior derives his superior wisdom to dictate to us foolish mortals just what "risks" we are allowed to take.
Other protagonists in the spat........
If you were in an operating theatre,(possibly as an observer) and KNEW the surgeon was departing from safe,established ,legislated procedure and had NOT been briefed on that departure, you would, IMHO be well within your rights to question him.
Just because you hold the qualification,does not exclude all others from knowledge....to suggest it does, is arrogant.
IMHO the legislation is flawed, incompetently administered and a diversionary tactic by politicos to obfuscate their bungling ineptitude.
Captain RULES the aircraft....notwithstanding the Aeroflot accident,( It's probably the ONLY accident in the history of commercial aviation in the civilised world caused by cockpit visitors) the FD crew KNOW they're in the front line if they foul up....the vast majority don't have a death-wish! They're paid to MANAGE...let them!
The brief outline of the Aeroflot accident demonstrates an extraordinary lack of crew management, discipline and procedures (Aviate Navigate Communicate, anyone?)....Hopefully all pilots learned from that....I'm sure it wouldn't happen again,if F/D visits were to be reinstated.