Another perspective for the OP, assuming that it was a real question, might be that, in Australia at least, doing well in mathematics is a pre-requisite for a number of the more prestigious and potentially well-paying careers.
If you want to be a doctor, or an engineer, or a dentist or a pharmacist, you’ll need to do well in maths, physics and chemistry to be selected for those courses.
In the area where I used to live was a large population of Vietnamese people, many of whom had come to Australia as refugees. Some of them had been professional people before they came to Australia, but had left everything they had behind, and on arriving here, had nothing. People with overseas qualifications often face an uphill battle getting those qualifications recognised in Australia, so many of those refugees took whatever jobs they could.
Many of them worked extremely hard and diligently to ensure that their children would have decent educations, and those kids take their responsibilities to their families very seriously.
I don’t think it’s unlikely that one of the effects you see is kids, who recognising what their parents have sacrificed on their behalf, determine to go into careers which might offer large salaries, so that they, in turn, can fulfil their responsibilities to their siblings and to their families.
I think if you couple that sense of responsibility with a cultural bias toward academic achievement you might explain some of the success of students from South-East Asia and neighbouring countries.
An Arts degree is well and good if you have the luxury of choosing a course of study for its intellectual benefits, but if you want to be sure you’re able to make enough money to provide for your family and increase their standard of living, you might choose to be a dentist instead of a PhD in film theory.