Does anyone double guessing the SQ captain's (or more to the point, SQ Flt Ops') decision on this diversion actually fly commercially? Or fly anything bigger than a C152?
Reading some of the opinions on this thread is like walking into a crowded aero club bar very late on a Saturday afternoon.
Try for one moment to guess the logistical nightmare (to say nothing of the cost, both in cash and very pissed off passengers) for the company finding 500+ beds in a port where they have no ground staff.
Then give some thought to the technical side of things, like who's going to fix it, with what and how you get the replacement engine to 'your' better diversion port.
One engine out on a four holer is definitely not a land asap situation unless there's some suspicion that the cause of the failure might be affecting (or possibly about to affect) either other critical systems or one or more of the other engines.