It started with horde racials. Blizzard buffed them into GOD MODE status, so many many many people went over who min max for racials. Then others started hopping over because their friends were jumping and they were lonely, as wellas streamer fans and fans of the world first groups like METHOD and BIG DUMB GUILD, all their supporters jumping ship to the horde. They then nerfed some bit, but people got comfortable on horde side and didn’t wanna pay $15 to go back so here we are.