Tipping is not only not compulsory but discouraged.
For kiasu sinkies tipping is not a culture at all...that's why the overall service standards are fucked up.
I used to stay near pasir ris/tampines area and everytime take cab back from airport alot cabbies will show me blackface, the rare ones that dun will get a big tip from me. This is the kind of service standards we are talking about.
Let's face it, taxi driving is a 'last resort' occupation here...many cabbies are the displaced ex PMEB/Ts that ended up as cabbies because they cannot do anything else....coupled with the blood sucking taxi companies, the forever decreasing income cause by rising costs etc....taxi drivers are a disgruntled lot.
Not using these as excuses but a fact or life for sinkies.
Sorry bro joe had to meet with such an incident...look on the bright side....encounter them often enough you be numbed liao....just like how sinkies deal with negative things about sinkieland.