You're oversimplifying. There is more than just one variable involved in a person's productivity. "Professional" people can be passionate as well, the difference is in how it's expressed.

Also, I'm not at all convinced that passion is the key component in how great games are made. From what I can see the best games seem to come out of a sense of professional dedication to the ultimate product and the customer. Someone who is passionate tends to pick something up and work really hard on it for a while, but release it half-baked and ultimately unfinished. Id software's recent work is an example.

Contrast this with highly professional game organizations like Valve or Blizzard where, yes, there is passion for games, but there's something else too: a highly professional dedication to polish, completion, continuous refinement of game mechanics, etc. The latter simply produces better games.

And, uh, duh that a high level of talent is not enough to launch you into a position of major influence. That should be obvious. Everyone thinks they have talent, and it's expensive to even evaluate those claims. The only practical way to discover the truth of a claim of talent is to gradually expand a person's responsibility as they prove they can handle tasks. That's the way it's always been, and that's the way it's gonna be. The good news is that software unlike most industries affords you the chance to do this on your own, like, for example, that guy who did Minecraft, or any number of other successful indie game developers. They could basically write themselves a check into any game design position at a major company if they wanted to.