Not only merit is required to rank up, we need activities to there's so many thread's about ranking up you may read them all, but for now the merit system is the hardest thing to rank up. There is a required merit and activities to rank up.
Activity requirement had been there before the merit system and is much needed. One should be a member here for longer time to be able to enjoy the benefits of senior ranks. Merit is not the hardest thing, it just requires the members to work little smart. You need to focus on areas where there is less competition for merits. For instance, I see a good probability of getting merits if you are doing analysis of stats related to the forum. Many of such threads got rewarded with good amount of merit points by senior members here.