I never press M, unless someone is spawn killing or other blatant intentional TW (since it says "intentional", not "careless"). However, I propose we do away with the M system, and replace it with the following:
-Eliminate the boring multiplier system
-Replace it with a more complex/varied reward system (objective-based and difficulty-based)
-Punish TWs heavily in this new reward system (XP/gold penalty)
We kind of have that right now, but good players will still get valour even if they TW like crazy, and bad players will never touch valour even if they never TW, so they don't care.