Why do universities in Hong Kong set up so many engineering majors like chemical, mechanical, Mining, and metallurgic as HK has no such industries? Why the HK government is willing to support such majors which will not benefit its economy?

That depends on how you see the role of universities. If you consider the sole function of the universities is to satisfy the need of the business world, then it indeed doesn’t make sense for Hong Kong to provide those classes.

But if you see university as a place for people to pursue knowledge, regardless of the practical use, then Hong Kong has done a good job in providing a diversified subjects for students to pursue higher education.