What matter the most is to see the point and .. well, merit posts only for their usefulness 
Usefulness to whom? I bet that Brainboss finds those posts useful. Well, at least for him.
Joke aside, if merits have been implemented to improve the overall quality of this forum, then I just don't see any reasoning for using merits in this way. Especially not by merit sources, since their responsibility for distributing merits is even greater.