Yes, you could be right with that. I guess not enough kids are playing Risk.
Although it can seem pettily nationalistic (and probably is to some extent), for quickly illustrating "You Are Here", and the relative positions of other countries to your own, centring maybe makes more sense than having some far away country at the centre.
It seems pretty common/natural in different countries too. I wondered if a 'most accurate map' exists, and found Authagraph:
