My Malay PHV driver friend says Chinese passengers are the best. No hassle, generally law abiding, no quibbling over fare.
Big Malay families at the airport are a nightmare - family of 9 with stroller insists on squeezing nto his Noah, refuses to split cabs, even when he tells them it's illegal and he may get summoned. He ends up cancelling job, pushing up his cancel rate.
Worst are Indians. They bargain and bargain and hold you up, the drunkards at night puke and refuse to pay for car wash, and uppity Indian nationals refuse to wait at condo gatehouse, insisting that he go to their lift lobby in the carpark which is against Grab's policy. So cancel job again. Taxi drivers don't stop for Indian men after 10 at night, but PHV drivers don't have that option.
This guy probably had some bad experience with Chinese passengers. To each his own.