The problem here is that you are interpreting a saved game as an automatic negative mark, when that was never meant to be the case. A saved game is just that-- a game that has been saved for later. It may have been saved because the parties involved agreed to resume later, because the game is currently being played, because it's an unlimited match, because the server crashed, because one player's connection crashed, or because one of the parties involved intentionally dropped the match.
Read that list carefully. Only one of those reasons is a negative thing. The others are just factual, and are perfectly reasonable reasons for having an unfinished match.
Note that FIBS has no concept whatsoever of a reputation. None at all. FIBS merely provides a factual piece of information-- how many unfinished matches are currently sitting on disk for a particular player. How you interpret that information is up to you. Repeat after me: the saved game count is not a dropped game count.
I am always open to well-thought-out suggestions for dealing with the problem of droppers. I use several criteria when analyzing such things, including my ease in implementing the solution, my estimate of the effectiveness, any loopholes for abuse that I see, backward compatibility and client compatibility, and any potential side-effects. Note that most things that are described by users as "easy to implement" are actually quite hairy and have all sorts of complex side-effects.
I would love to hear a workable solution to the problem of droppers. Please, surprise me!