Although I don't like being on the receiving end of rage... I don't think it should be removed at all. Do some people abuse it? Sure but there is ALWAYS something that will be abused. The rage feature gives hope to someone in a match who be getting pwned left and right and if they get in a kill or two off of it... that can be the difference between them rage quitting forever, and continuing to play the game.
Can it turn the tide of a match? Sure. I have no problem with that. It's not a secret what it is, what it does, and you need to watch out for it.
The logic that "everyone is high level now and it is no longer needed" is in my personal opinion... silly. There will be people that buy this game later on that will get trounced. Having the rage available can help this stick around as I stated earlier. When you have NOTHING upgraded unlocked, it is really the only advantage you can gain when a newbie. It should stay.
I get my butt handed to me now and again. I may be getting owned playing with randoms against a group that is clearly a team, we may be outnumberd and I keep catching the double triple team.
Now if I'm getting trounced... I certainly am gonna use rage when it is at my disposal. I don't intentionally get it, I don't die on purpose to have it. If I a legitimately getting beat, yeah I'm gonna use it so I can at least help my team a little instead of being a detriment to them. Just because someone is a higher level does not neccessarily mean they are super skilled. Level advancement is based off of XP and not skill, and with double and triple XP happening regularly, any schmoe can be a high level without neccessarily being what some consider "good."