I am a St Jo old boy too. I graduated many many years ago and I could only remember the happy moments, such as singing contest, dancing contest, football, table-tennis, good teachers, .....
I don't recall any long night of assignment mining. In the old days, students at St Jo kinda competed to finish as much assignments in the classroom as possible (we tried to finish them between classes and after recess). At the end of the day, we compared and bragged about how much we completed. It was fun. I do think it depends.My peers remember the play time only. As the parent of a st Jo and being an old boy, I do think it is a false perception that it is a torturing school.
Hard to say whether St Jo is more "hea" than private and direct subsidies schools as it strives for better academic results to be recognized as one of the top schools.
I don't understand why people always refer to the old times when they were old boys or old girls of the schools in discussion, those were the old days, come'on. Nowadays, the workload in primary schools are much heavier than in the old days, and perhaps the comments of the parents with children studying in those schools now would be more relevant.