Not all people are creative and passionate about photos. By this kind of platform, because of there is reward given I can say that they will try their best to be creative for the sake of the rewards. Skills can be improved so I think all people can do participate in this platform.
Also I think it depends on how much you can earn, as the developers still haven't given any information. You can be a professional photographer and upload a dozen of photos and earn a dollar, will you continue participate in the project? I doubt that.