Sad to say but there are 1498183 members on this forum. Do you think they can manage it all? Administrators and staff are few but they are doing there best. Yes, there's a problem with this merit system but majority of the merit system helps the forum or the newbies to become a good posters. Like me I'm just new to this forum, I agree that ranking up isn't not easy like before the update of this forum because every rank requires many merits to rank up.
I agree to your suggestion but it would make the admins work more difficult, all the admins of the forum can't go and check every post of all the people in this forum there are many msny users. All the admins definitely would also have their own work to do, that can't just sit here whole day checking peoples posts and rewarding them merits right?