Its a punishment if they log in occasionally and don't do anything. If they log in occasionally and do something they get no penalty.
So someone who logs in, holds court, then logs out, twice a day, for a year, gets no penalty.
But someone who logs in, sends a dozen letters every turn, but takes no actual *action*, gets penalized, even if the result of his sending letters is an amazingly fun war.
Your proposed is broken at its most basic level.
There is no point in discussing this.
