There is actually one in Beta progress. Check the first four/five top threads in the Beta releases forum.
As for the bulletin board admins being selfish?
They did take their time and effort to code it, and they aren't obliged to 'share' it with anyone if it's their own.
Would you share your TV set/computer with someone off the street? Unlikely.
However, greed can be interpreted from this, if people don't have the knowledge of coding. Coding is a skill which requires YEARS of patience. But hey, I agree, it can be a tad greedy ;).
afterlab's battle system for example: It's unique. Nobody else uses it. If everyone used it, there'd be less chance of users visiting his board (notice to afterlab: When are you going to bring it back, me and my 3 mates are missing the fun *crys*).
Anyway, back to the point.
If the bulletin board owners want to share them, you should be very grateful, because they could just as easily charge cash for it.
If Neo complete's his, and it's free, he'll get the world of credit for it :).
Battle systems for vBulletin are like trying to fight for the best sweet in the tin of Roses. So much competition.
Don't let it get to you, I'm positive one day some hacker will release a wonderful copy.
Bless them when they do :D.

Dave.