1. Create a shit ton of fake accounts.
2. Spam!
3. Report with your main account.
4.
?
5. Profit.
Steps 1 and 2 are not even necessary. Just pick a random altcoin bounty or ANN thread and you can report every post for being low value or spam and still be marked "good" >95% of the time. Combine that with an automated tool such as suchmoon's, and you could be top of the merit leaderboard in a single day. Doing so doesn't really help the forum, though, as no one is reading those spam threads anyway.
But yes, it is far too easy to game, just like all the previous suggestions of the same thing, or of reporting competitions or financial rewards.
Still holding out for badges, but I remember theymos saying there was some problem with implementing them?
Edit: Found the quote.
Sorry for the wait, when I went to implement this it ended up being quite a bit more of a can of worms than I originally thought because of opting out, preventing certain report-count-padding strategies, etc. It's still on my to-do list, but there are several things above it.