OB1
Jedi Master
In many ways, DDB is now a gaming platform similar to Nintendo, Playstation and Xbox. But let's not forget that the videogame industry was once dominated by Atari and Sega. The point being that when a product or service get's mass popularity, competitors will appear and just because you are the leader today, doesn't mean you always will be. Nothing about what WotC is doing with 3rd parties strikes me as anti-competitive, and in fact probably makes it more likely that a strong competitor will eventually appear.