They judge submissions based on whether the players will like them. They also need to consider making a variation of highly desired gifts and less desired gifts based on composition, all the while maintaining style consistency and quality. You guys are so butthurt about your "wasted hours" that you forget that it was more than just a skill-based contest (not to mention most of you complaining didn't submit the best looking graphics in the first place).
Come on guys, it's Christmas lol