I have not had the "pleasure" of flying in that part of the world, however, a couple of very experienced colleagues that did, for some time, intimated to me that if you did not accept to routinely fly through weather that you assuredly would avoid in Europe, you wouldn't operate any flights.
I also operate in Europe and I'd say that is a fair assessment.
Down low, if you 'never fly through the red' on the radar sometimes you'd never make it to the airport in places like SIN. You can turn down the gain and play with the tilt and try to find structure but often all you have is rain with very little turbulence.
As for up high, several of us have come down to the PPRuNe altar and testified here about those cells that just don't paint but have a tremendous kick.
Just as you get used to the icing, fog and low ceilings in Europe in the winter, convective activity is a common challenge year-round over the South China Sea.