What Is This Idea?
The idea is simple, reconfigure the forum, as well as the merit system, reconfigure it so that if a user does not earn atleast 1 merit in 120 days, that user drops he's current rank for the lower one, and if in another 120 days, the user still does not earn 1 merit, he or she again drops the current rank for the one lower, just like that until that user is back to newbie... This can only apply to junior Members rank and above.
Will it interest you to understand that if everyone in the forum will engage in quality posts at everything, there would be no need for the merit system. I understand that the merit system was introduced due to extreme spamming and shitposting by account farmers in order to rank up.
So, it will not make sense to demote a user because of his/her absence in the forum for a long time thereby negating their previous contributions. There's already a penalty, which is, if you don't get merits you will no longer grow in the forum, remaining stagnant is the price to pay.