Hmm... I understand better now... I don't really see the point though... if you can only give 1 point to a user, it makes more sense to use the "vote on users" system. Also, I'm not sure how easy it would be to implement... it looks like you need every vote available when you do that calculation... I'm not good at math anyway.
Right now when you vote, MyBB simply adds or subtracts a point from a user's overall reputation number. With your system, it would first have to load every vote you made for a certain user, do the calculation, then... uhh...
How would it update the user's reputation number? It would first have to delete the previous reputation change you made, then add the new one... right?