But the sample size could be a billion and it wouldn't matter if the process that generates the population isn't random. If Blizzard was just hiring people off

But the sample size could be a billion and it wouldn't matter if the process that generates the population isn't random. If Blizzard was just hiring people off the street then yeah, sure I'd expect a bell curve. But given the whole recruitment process, it's not necessarily going to form a bell curve. Plus, the implementation is usually at the manager level - so each manager has to meet a quota of x% good, y% okay, z% bad etc., and each manager doesn't have 10k employees.