This game is for a young or unknown designer. It's their chance to establish themselves and build their portfolio. As a professional who makes a living in design, you are not obligated to compete. Though, you are still invited.
It was Skype's choice to put on this contest, and it should be assumed they know it is possible they won't get as quality a final product as possible. There are plenty of projects out there for quality designers to work on, and it bothers me that so many designers complain that free/cheap client work is such a pain in the community's ass.
Without a doubt, the type of client who wants to go that route is someone a designer of your talent wouldn't want to work with in the first place.
Right?