Well it worked fine for Impulse Airlines through all their years of operating as themselves and as Qantaslink on B717. It suceeded on a number of levels, not the least of which was team-bonding, mutual respect, and understanding. The policy was introduced because we were trained by the aircraft manufacturers, not by some ego-maniac who thought that Aussies "know everything".
I suggested the policy to a QF captain with whom I trained in the RAAF. He thought it a superb idea, as he had suffered dual pilot incapacitation, which was only resolved when his appendix burst, allowing him to land the aeroplane. He could have been administrated palliative medicine. His suggestion to QF management was met with the same guffaws as I witness here on this site.
The purpose of the F/A in the flight-deck is solely and utterly to manually open the door, letting in 50% of the crew. This policy was totally thrown out with the "Ansettification" when the A320 was introduced, and pilots no longer helped the team straighten the cabin on turnarounds. The cabin crew were deemed by the new management to be replaceable, and not committed to the job anyway, even those with 20 years in various airlines.
This term has got me into so much trouble in my life, but now I'm retired I'll use it with abandon. Wait for it...
If you are such a sky-god that you never need assistance nor recognise other team members abilities, you are FROGSH1T!
If you are such a company person that your security will weed out threats so efficiently that it will never be an issue, FROGSH1T!
If you believe that your company knows more than the decades-old company that built and test flew your aircraft, FROGSH1T!
I go by train and ship these days, because most of you (at least on this thread) are goats, and my shepherding days are over. The times are a'changing, get used to it. The whole world is marching to this beat, and you guys are out of step - but you're NEVER wrong. When you buy your next coffee in the terminal, what's in it? GBH, LSD? You are never invulnerable.