That's not too weird in HK now. There are too many rich people in HK!!! They just spend $ to achieve what they want their kids to be. My daughter's KG has many parents spending over $10k each month to boost their kids preparing for primary school applications!!!
Tutorial centres or private tutoring could be useful if parents are both working and nannies are not entirely suitable for school work supervision. But their functions are more like daycare centres.
I heard one Division One primary school actively discourages tutorial centres or private tutoring. I agree with that approach - after all, there are evidences that intensive tutoring at tender age will destroy rather than stimulate creative thinking.