OK - it's the other side of the world so in the one sense it doesn't matter, but...
For various city careers these sorts of unpaid internships are massively advantageous for future graduate job applications. In my area (law), the competition for unpaid internships/vac schemes is often *as competitive* as getting the actual job itself and when you're applying for careers post uni having a selection of internships & work experience on the CV is advantageous as an absolute minimum, and many firms require it. Although they're unpaid, time and resource reasons means that only a limited number of these opportunities are available each year.
So - when well connected wealthy people can arrange these for their children on an informal basis, when everyone else has to spend hundreds of hours making applications in the *hope* of obtaining one. This gives the former a serious competitive advantage in securing well paid future grad careers.