Flights KL 837 (AMS-SIN-CGK) and KL 835 (AMS-SIN-DPS) and back make a stop in SIN. Why ? Usually most flights to SE (HKG, BKK, SIN, KUL) Asia are nonstop and as there enough flights AMS-SIN (KL and SQ every day at least one). Is it not allowed by Indonesian or Singapore government to use their air space without landing ?
A flight AMS-Bali would take 14 hours instead of 16 with stop in SIN and conserve lots of fuel and the aircraft used (772) are able to fly that distance nonstop.