I completely agree 100%!!!
Being a good person can be difficult to some, but in league its super freaking easy!
Step 1. Don't be a douche.
Step 2. Be nice.
Step 3. If someone makes a comment that gets you tilted mute them right away then move on.
Step 4. You have so much higher morale this way, you, and possibly even your team, will play better!
Its so simple it baffles me that so many people can't do it.
If a teammate is sucking, you think flaming them is going to make them play better? OF COURSE NOT! Flaming em will only make their morale lower, and as such play worse. Friendly encouragement will actually bring their morale up, and they might even play better cuz of it.
People really underestimate morale. Its one of the most important factors to not only playing and enjoying this game, but also winning it.