I don't mean to rain on your parade, but without details of the kind of private school you speak of we really can't say much about that story of yours. To be sure, there are a lot of shady, dodgy, or not very well run private, 'international' schools out there, and they may be profitable for many reasons, one being the attraction of parents who prioritise English-medium learning for their children given the unpredictability in public education policy, the other being the considerable wealth and influence of the owners/operators of such schools. I think most schools hire principals for their experience and ability, while the average graduate who hasn't even left school for longer than 12 months will hardly be able to demonstrate adequate quantities of either.

I'm not saying your friend is merely an average graduate. He/she may be an exceptional individual for all we know. But the reality is that there are a lot of people around the world doing Arts-type degrees (International Relations, Politics, Sociology, Languages, Asian/Oriental Studies, History, and Philosophy which is relatively rare) and most of them are not destined for huge corporate jobs. They are more likely to venture into politics and government, NGOs, journalism etc. Of course some may be qualified for banking jobs, and we have all heard the stories of investment bankers with Philosophy and Sociology degrees. I have also known people with upper-management jobs in banks who studied languages. But note that the school they graduate from is usually quite exceptional.

The backgrounds of those holding/having/who had top jobs who are not self-made (e.g. Michael Dell, Bill Gates, Steve Jobs, Mark Zuckerberg, Roman Abramovich, Henry Ford, JP Morgan) is quite clear - they usually have practical or 'applicable' degrees (applicable here refers to those not traditionally seen as practical, but which can have commercial/professional applications and which are in demand, such as Mathematics and Physics). Most of them have some background in Business, Commerce, Economics, Finance, Accounting, Management, Engineering, Mathematics etc.

Now, if we talk about practicality and the Malaysian mentality, it's not easy to change what is in place. Preferences for Commerce or Quantitative degree-holders may be in policies. Many 'Business' graduates are hard enough to train once employed, so management may not want to take a chance with Arts graduates, who have every possibility of knowing less about Commerce, Banking and Finance than 'Business' graduates.

It is a good thing to have a passion for the subject you study.