I agree with OP in 100%. In DII it was at least somewhat explained why we see only humans, than Dragon Commander came- and all races were present (apart from orcs). Original Sin is too much of a cliche for me. Orcs- evil, imps- evil, elves and dwarves- not in game (apart from single elf) and so on. I'd honestly prefer another game in 2d- like DD- with more diversity, than 3d game, but with hundreds of constraints...