I don't get raging, league is fun!
It may just be my personality, but I don't get why people rage when they play games. Games are for fun, right? IMO, if you're not having fun, you're doing it wrong.
When someone on my team feeds, I don't care. I've done it, you've done it, we've all done it. Maybe they're new to the game/role/champ. Maybe they're just having a bad day/game. Why ruin your own day by reacting negatively toward it?
If you find yourself raging or being toxic, do you ever stop to ask yourself if you'd rather do that than just play and enjoy the game?