As a doctor, I'm sure you appreciate that the reason that you can diagnose, treat and surgically remove a potentially life threatening cancer is because of the hundreds (if not thousands) of years of experience and learning by countless physicians, scientists and crazy amateurs who came before you, much of which involved a great deal of trial and error. (Trial and error being fundamental to the scientific method, after all.)
And even after all that, we're still a long way from understanding everything about the human body, how it works and how it goes wrong, and how to cure all the ailments that can befall it. Mistakes are stil made, and not every medical procedure goes as planned.
In contrast, computer gaming is little more than 30 years old, massively multiplayer online gaming is still in its infancy, and game design is still in the process of being recognised as a unique discipline in its own right. Gaming is also a highly subjective field, where the very thing that one player may enjoy the most about a given game is the exact same thing that another loathes.
Don't get me wrong, I am not in any way suggesting that medicine and game development are comparable fields, but the fact is we know a hell of a lot more about one of them than other, at this point. Doctors get years of training, and if they have a question about something, they normally have easy access to a vast body of acquired knowledge, either in the form of written material or more experienced doctors that they can turn to.
Most game designers are self taught, have to learn 'on the job' and if they run up against a problem that neither they nor their team has bumped into before, they generally have to work out how to handle it themselves.
Erm, how do you know that things like profession balance aren't being worked on?