From my understanding, when our forefathers determine PH for all Races. They tried to be fair and consult all Races representatives. This was how they determine PH :
1. Chinese - CNY (2)
2. Malay - Hari Raya & Haji (2)
3. Indian - Deepavali & Vesak (2)
4. Others - Christmas & Good Friday (2)
the rest like May Day, National Day & New Year's Day are common.
Some may argue that Vesak Day was mostly celebrated by non-Indians. It is true that it was hijack by non-Indian. However, it was determined then and it is not easy to change without opposing parties - Indian or non-Indian. Maybe during that time there were significant Buddhist among the Indian or simply Buddhism originated from India.
There is no right or wrong when come to treating its citizen. There are always grievances among all Races. As I always mentioned, all Races are different. Culture, Custom, languages, preferences, habits, beliefs etc.
There are no ending to grievances, even among each Race there are dog lovers, vegan, gays etc .... As long as it don't impose or restrict your choices, I don't see any problem.
On the Hindsight, can low IQ society apprehend the "concept of reasoning" - I doubt so. That is why certain countries or Race remain backwards.
Race and IQ