Trolls will be trolls I suppose. Every now and then I have someone on my forum who abuses something, but it is what it is. On the other hand, I have made some modifications to the reputation system on my forum to give it an actual use instead of just another statistic. I use it as a way for my community to reward quality content and to punish poor content. People who have high reputation have access to greater privileges. I really like the idea Discourse has, where they have a trust system and at the final tier users are allowed basic moderation privileges. Using group promotions this is achievable in MyBB. So basically, strong participators in the community, backed by the community, will eventually be able to aid the community. But yeah, I hope you do implement the reputation addition, it would be very much used and appreciated.
TL;DR - it would be one step in the direction of modernizing MyBB
TL;DR - it would be one step in the direction of modernizing MyBB