Just because a few lines of code interact with the same database and APIs, they have to be free? I don't think that is really a good way to look at it.
The owners of Wordpress should have no rights over images, stylesheets, and html code created for themes and plugins. These work wiithout wordpress, and are portable to any platform.
If a designer is frequently competing on 99designs, they are probably unemployed. Of course those people are going to get angry.
High-end design is an extremely intricate, time consuming process that you really have to put your heart into. Rather than a proper design process with one on one consultation, concept development, drafting, etc the entrants have to create a design based on a short project summary in hopes that theirs will get picked.
Many of the 99designs entries I've seen are just flashy, trendy designs that really do not serve the marketing purposes they are intended for. They often look great, but do not create an "identity". Artistic but non-professional. That is not the fault of the designer - it's a fault in the system.
In short, if you're a designer and you are using 99designs for anything other than practice, you are wasting your time.
But BP is definitely making "Photoshop" a household name. And like Google, it's becoming a verb.. Adobe should be happy with all the free press.
Everything that can be invented has been invented. -- Charles Duell, Director of U.S. Patent Office, 1899