I think this is a very closed-minded comment, but I'll try to respond...
1. Python != Java. It's as simple as that. I'm not nearly good enough at Java to take on this kind of project, and I have no idea whether the others have even heard of Python.
2. People do this stuff as a hobby. There's a lot of satisfaction from seeing what you've managed to do, and from learning to program like this. I'm under no illusions about the likelihood of finishing an engine, but I'm gonna try!
3. Because of how these forums work (and make no mistake I agree with it) you need to have something to show before you make a thread. I did about 4 months work before I posted on here; I assume the others did the same. You can't be expected to scrap all that if someone else posts a few weeks before you.
4. Working together is still possible. You'll notice that danice123 posted a link on this thread, and I would be happy to help anyone else who wanted it.
5. Variety is good. Not bad.
I think that covers a lot of it. I understand what you mean, but really there's nothing to complain about.