Activity checks are not a waste of time, it keeps the clan system tidy and not over run with hundreds of clans like we have today. The general activity check needs a good fair structure that works with the player base and the standards. If the clan system was managed and run correctly through out the years we would not have this issue today.
The change will not increase activity nor will help draw older players back into the game, most likely it will boost the % for a small time then you will notice it drop even harder then it is now. (failure on a failure)
Honestly if Toribash was trying to give off an image of what a clan should be and what it should represent then they should not have let a clan become official within a month that gives off a bad example of what is expected while you have clans who not only put effort, time, and initiative into there clans but gives off a more than excellent example of how a clan should act, what is expected, and the effort they put in to help other players achieve there goals.