ANewPosterAppears, whose sockpuppet are you?
New poster + disagrees with you = must be a sock puppet, eh?
The problem is, we are. If Pathfinder were the far and away winner, I'd probably be playing Pathfinder on a weekly basis. If D&D 4 were the far and away winner, I'd probably be playing D&D 4. As it is, I'm playing D&D 3.5. If D&D 4 manages to take most of the D&D market share, my Pathfinder books will lose most of their value, and I'll probably end up playing D&D 4. If Pathfinder manages to take most of the D&D market share, I might be able to find a Pathfinder game with less travel time. So, yeah, there are consequences to me as to what the world plays.
This is assuming it's a zero sum game, an assumption I see often in these edition wars (though typically from only one side). That's a very high assumption to make! Now, let's see, I've played 4e, 3e, Pathfinder, and 2e. I guess I prove your entire assumption wrong since people like me cannot exist for your assumption to work. After all, if people are capable of playing both games, then there's no intrinsic tie to one game going down and the other going up! Whoops!
Fact is, when it comes down to it, the consequences you make up are non-existant. The only consequence of both games doing well is that you can't lord it over other people. You'll forgive me if my heart doesn't break over this.