I’m not familiar with how they work from the top down but I do recall a college course that talked about how with more people the quality can be lost. You have a lot of managers and people reporting to others and somewhere along the lines the product or service is affected because of this. It makes it far more complicated I suppose to get things done, as well as see the overall outcome.
Or anyway it had something to do with communication, and with Blizzard having a very large dev team that likely makes communication tougher I believe.