and for safetys sake would rather have diverted , and flown on a fully fit aircraft.
There's no such thing as a fully fit aircraft. We are paid to assess the risks once the aircraft is airborne. Perhaps we shoud also refer MEL or fuel decisions to the passengers as well. Perhaps for safetys sake we should all take an extra 20 tonnes of fuel each flight? We could have a vote on it at the departure gate.
but perhaps these 'untrained' passengers rightly felt that they may have been put in danger and that the 'safety priority' was being conveniently sidelined.
No, they wrongly felt that they might have been put in danger. Thats rather the point of this whole 35 page thread in case you hadn't noticed.
an engine out landing is only practised in a simulator - lifelike as it is, nothing beats the real thing... supposing their approach had 'become unstable' in their new found first 'real' experience of this situation, or the weather at Manchester had suddenly closed in - as it was doing over those few wintery days ?
If a three engine approach in the simulator wasn't very close to the real thing then they wouldn't be allowed to train pilots in the simulator. The whole point of the simulator is that it is a very close approximation to the aircraft, it's not just an expensive video game. And so what if the weather had 'closed in' at MAN. What do you thing the aircrafts autoland capability is with an engine out? (You evidently have no idea, so I'll put you out of your misery and tell you its excatly the same as with four engines).
If the engine had failed on pushback 15 mins earlier, they woudln't have continued the flight... so would it not have been prudent to divert to somewhere else heading East rather than make an ocean crossing ending with an emergency diversion ?
You really haven't read the thread, have you? Once you're airborne you don't need the fourth engine for take off requirements, it is perfectly safe and feasible to continue on three, but not to commence the take off roll on three. Thats the difference.