An engine shut down on a 744 is not an emergency (given the definition of the term or the 'spirit' in which it is used), especially given the situation in which they found themselves. It just about qualifies as a non-normal but only because it's usual to have all 4 donks spinning. A Jumbo without one of the engines is hardly noticeable and most times would not even affect the operation, especially if it happens fairly late in the flight without hours of travelling a bit slower for the same fuel burn as four engines ahead of you. With only 1.5 hours-ish to run to LHR they would have been pretty light and the eng out page would almost certainly have told them they could have stayed at their present flight level, if they so wished. I have absolutely no idea why they decided to divert to FRA but I'm certainly not going to second-guess the crew. They did it for a reason or two and that's that. Good decision, well executed, end of story.
Yes, the pax are inconvenienced and, especially given QF's recent lacklustre performance, they are angry. But (a)they are safe (and that, of course, is the name of the game) and (b)there are millions of flights per day from FRA to LHR, so they won't be there very long.
Again, more sensationalism from journalists looking for non-events to write about. They'd be far better concentrating on how windscreen wipers on my ute are not really up to the job and could well cause an accident in torrential rain.
The only time I ever found engine failures vaguely 'interesting' on the Jumbo was losing 2 on the same side with lots of terrain around. Never done it for real but places like Bogota, in the sim, with 2 out on the same side at max take-off weight makes it sporty and probably worth declaring a Pan
.