Any sort of negative influence on your team or against your enemy is equally as bad. Afk, intentionally feeding or simply ignoring your team by refusing to cooperate with them is simply equally as bad. Also, no not "all" players make this game a terrible place to play and no, the majority of the community isn't part of the problem.
Players that are part of the problem cannot keep a stable account. Players that are part of the problem does not have the mindset of keeping the game friendly and have no self-control of keeping this video game that is meant for entertainment fun enjoyable. Which is why in the end, they're punished. The major problem with toxicity are the players who come into this game not reading the Term of Use thinking they're invulnerable because they're behind a screen. Players who have no temper control, no self-control and no moral understanding of respect always meet their end with a ban. The major problem of the toxicity are the players who come into this game thinking they're reaching for the stars of being part of a major gaming community that think they're going big. Thinking this is some sort of life trial or a life-changing job. Little do any of these toxic players know or could care less to know, is that this game, created for teamwork competitive entertainment fun, is meant to be, yes you guessed it, FUN.
The point is if you're not here to have fun if you're not having fun if you have no self-control or no understanding that this game, League of Legends, is meant to be fun. You're not meant to be here. This game is not meant for you. If at all, any competitive video games that require you to get along with your team to seek the rewards of winning is probably not meant for you.