There seems to be a lot of "LCC blame" going on here.
What support does any airline have when it lands at an aiport where it doesn't have any flights.
One could ask the same for Qantas on the same route, but then it doesn't fly to the capital of our largest trading partner (ie Beijing).
What if a SIN-LHR flight had to make a medical emergency stop at Istanbul , Aleppo or Baghdad and the crew went out of hours.