Reward is a cleaner and more organized and welcoming board for genuine discussions and fun for all instead of select few. Otherwise those who do not report garbage kind of deserve to sit in the middle of it. After all they could get it cleaned by reporting...
We do reward member for genuine help or good conduct or good suggestions when they come up. So one may be awarded for reporting something which may hurt NB seriously or the likes.
But the idea of regular reward in lieu of reporting general forum rules breaking defeats the purpose... People may spam even the report section you know... last time someone mentioned that reporting rule breaking might help admins in choosing mods and instead of getting genuine reports we were flooded with some of the most ridiculous reports... ( not all some were reporting correctly but many were just.... )