Fundamental misunderstanding of "climbing" attitude
Sometimes your team is bad. It doesn't matter what you do, you are destined to lose. That doesn't mean that everything that happened is your fault.
People love to trot out the "f you lose it's your fault" attitude without understanding the nuance of the statement. "The only constant is you" only means that you can only change yourself. You won't win every game, but you can try to improve. It isn't your fault bot went 2-20. You just can't do anything about it. So why worry?
This isn't a green light to feed and blame someone else. That is, however, what it is used as. I'm so sick of hearing people preach about "Riot's scientifically proven" thoughts on the matter. Riot makes video games. They are not psychologists.
Sometimes your team feeds. It isn't your fault. Play your best, and you can win more than you lose.