Avman,
A 747-400 has four engines and four hydraulic systems. If one engine quits, it is left with three engines and three hydraulic systems. It is (more than) reasonable to assume that the crew of this particular flight would not have continued if there had been any risk. Yes, they have to fly at a lower level. Yes, it uses more fuel. So what? They did the sensible thing and landed somewhere closer. Wrt their alleged fuel problem. How do you know that had anything to do with the engine failure? It may have happened anyway.
A 777 has two engines and three hydraulic systems. Does this mean it is less safe than a three engined 747-400?
Please explain why you feel that a three-engined 747-400 is unsafe in cruise. After you've done that, please explain why you are happy to fly ETOPS.
If you're that concerned, take the train in future.