Bad behavior has spread like a virus over the years and it's Riot's fault.
I have played this game for 4 years. In those 4 years, this game has gotten worse.
Early on there were more people who straight dropped out of the game, or fed to ruin the teammates game. This has gone down.
In place of obvious trolls, we have players who just stop trying. They don't afk, half the time they talk shit in chat, and half the time they time they just quietly wait for the loss.. then report and blame teammates.
The worst players in this game use the report system.
Riot has restricted natural social regulation. You can't talk about making plays without ruining a game, it makes players mad. You can't tell them to keep trying, because they will will dig up every small negative aspect they can as a point not to continue trying. This happens as early as the first death in a game in lower ranks.
If Riot never created this system that bans based on chat logs (WITH NO CONTEXT), backup up by player reports, THE GAME WOULD BE BETTER OFF RIGHT NOW.
The players would be more informed. Right now we have the opposite behavior of what we need. Teammates bandwagon toxic players. They don't bandwagon attempts to play and try to win.
Bad behavior, and pure ignorance, has spread like a virus. And your 20 something's in charge of every iteration of the ban system are not qualified, and they can not see the bigger picture.