I don’t know that is is, but there’s a very reasonable rationale to fly via KUL: price.

For example (in SGD):
MH: 25-29 July SIN-MEL rt: $835
QF: 25-29 July SIN-MEL rt: $1336
SQ: 25-29 July SIN-MEL rt: $1880

I’d take the extra hours flight time if I was saving SGD500 a person. For a group, that can be significant.

And I say that knowing that the MH A380 is not a great experience anymore, way too tired and in need of a major overhaul, but hard to argue given the (last minute) savings.

Again, if it is due to Singapore school holidays, the decision seems very last-minute given they end this Saturday...