That's true of the parenting style of any culture, no?
My mother did always say she wanted a third child...jokingly saying she may be able to then complete the 'Holy Trinity' of lawyer, doctor and accountant.
It's no concealed thing that Asian mothers are pushy - some will demand and coerce a child into a profession of their choice, others won't. Same for other cultures.
Generalisation and all, but Asian mothers will be pushy over everything. The writer may have scoffed at drama and PE, but Asian mothers I know wanted an all-rounder - music, academia and sport. So, in that sense, there's no limitation. The kid won't necessarily think 'I really wanted to be an accccccctor, but I can't just because I wasn't made to recite Miller for 5 hours a night'
Bottom line - mothers want to boast. And that's true anywhere you go, I think. If she can blab that her kid won the prize for acting, heck, that'll do.
Side note - my mother encouraged/pushed me to do Speech and Drama, so not everything was about geometry.