They said that those abusers will soon get out of merits and thats true, but those deserving to receive merits will also get a lower chance to get some.
Yes, something like reversing the merits in case an abuse is confirmed would be good. But the admin has already ruled that out in his comments. I can understand that doing this manually would take a lot of time and thus not practical in the long run. That is why there should be limits at the first place to send merits per post, per member and so on.
First allowing abuse through loopholes and then spending time finding and reversing the abuse is a lot of precious time wasted.