I'm pretty sure the medal system was originally conceived to cut down on flaming that happens when you can clearly see allies' scores. I think to that end it is relatively successful.

My issue is it creates a different kind of fight based on ambiguous information. Unless you are really shitting the bed with your hero, you have some combination of medals in either obj time (tank), healing (sup), or elims/damage (the fun ones). Everyone has some reason to think they're justified and someone else is incorrect because no one really knows how they're doing relative to everyone else. By removing information from the game, flaming fights have been replaced by miscommunication fights.

The obvious conclusion is humans are animals who enjoy fighting and omnics will inherit the Earth. But if I'm throwing ideas out there...

1) Remove medals entirely, but if you do that get ready for people literally saying their kills or damage and lying about it half the time.

2) Replace medals with 'rate of change' graphics you can use to figure out if your hero is a walking war crime or getting hard countered by a hero on the other team. Rate of change is a constantly decaying stat, so the downside is people will misread it and kamikaze at all times trying to maintain whatever graphic represents good performance. The upside is smart players will use it to climb, flat line, then check periodically to see if they're dipping. And oh look the enemy lineup is right there to help you draw more conclusions.

3) Replace personal stats with team stats, then give players the option to examine their personal stats for that round for the entire duration of the end game period.

Again, people are going to fight and flame either way, any other tricks from other games?