Because back in Vanilla and TBC, everyone already had the concept of min-max right? No way I did MC as Druid healer with a couple of greens, right? No way I learned how to play PvP with people that actually understood strategy, right?
Because vincentwolf is always right, right?
True that Horde racials give the edge when you can actually use that edge. Until then, you have to work a lot and hard, son. Furthermore, weaker racials produced better Alliance players.
That's my 14 year of wow experience for you. If you think you know better, I will not stop you from making a fool out of yourself.