Ok, i understand many of us may get frustrated at the game, our team or even the enemy. But do not throw the abuse around in chat, if someone merely asks you a question about your build or why you attempted to kill an enemy who blatantly wasn't going to die, don't reply with "f*ck you" or anything along those lines. People who inquire are not being sarcastic with this question or trying to anger you, they only want to know why. If someone gives you advice don't turn it down or ignore them because then when you complain about how you can't get anywhere you've only got yourself to blame...unless it's legitimately the enemy outdoing you.
For example i played a ranked match as Thresh, we had a decent looking team and could of won, but because nobody listened or communicated we lost. A Gnar who went top against a graves built into a BOTRK first...i told him he should get armour, 10 deaths later and with finally obtaining his BOTRK did he start getting armour. He was useless throughout the game but i didn't insult him. I left that to our Caitlyn who constantly insulted him however she was just as bad. An Annie who got way to cocky and at one point after taking a Jinx rocket to save her there was no appreciation but they're quick enough to pitch into you when you leave them to die. As for our Shyvana she didn't gank nor did she really do much for the team in general. I know this may just sound like me whining about my team but lets face it, when we have good sportsmanship of people who are friendly even when you are losing and they're still giving you confidence and being nice, i feel a lot better.
On top of that, you play the game on a keyboard, the only reason not to talk with your team would be if you do not speak the language or you have one them "gameboards".