[NTJedi]

Well by giving some races bigger advantages it allows more variation when going against AI or human opponents.
For example if an experienced player wants to introduce a rookie to the game most likely the rookie will be suggested to take Ermor. And the experienced gamer would play one of the weaker races and a weaker pretender. As a result a good game can be played... if all the races are equal then the only way a veteran could easily introduce a rookie would be by editing the .map file or installing a mod.