This is pretty darn anti-social when you think about it. You're essentially saying "good game, you suck" which invalidates the gg. what ever happened to "gg wp" or just "gg" .. We're "supposed" to be trying to create a friendly playing environment, and 40% of our players are basically ending the game with "you're crap compared to us." you can say "ez" to your own team but doing it over all-chat is essentially grinding your opponents face in the muck and making what could have been an enjoyable game for all into a sour finish. I've even seen it on games where a team has lost the entire game, turned aorund and managed to win by the skin of their teeth, and team-mates on my side.. or the other, are saying "ez" on what was obviously NOT an easy game.
I'm not expecting this to accomplish much but if I raise awareness and even 2% of players go "oh yeah, maybe I'll stop being a smacktard". Then it's been a positive influence.