The concept is really rather simple. If you want to improve something, and you have the time and skills to do so, then just do it.
There's no need to go @#$%ing programmers around for doing this or that. You can give suggestions, but since everyone is doing this in his spare time, you can't obligata anyone.
And about being open source, that's the beauty of it, there's no way back. I contributed code to the project, and as long as I don't want to relicense it, it's gonna stay open source. Every programmer that ever contributed to the project has a veto on changing the license of the code. Just like every artist that ever contributed to it has a veto on changing the license of the art stuff. So in short, the only way to change the license is to start over.
I'd appreciate it if you'd come here with a more open mind. Getting a finished game isn't a very big priority. The artists and programmers contributing here mostly do it because they like to learn stuff, improve their skills, or just like to spend their free time in this group. Making this game work is actually part of the game.