The actual toxic and destructive players to the game

"Well we'd be winning, but our adc doesn't know about lethality"

Excuse me, i didn't know that other players got to decide what is the correct and incorrect way for ME to play the game.

[slayer-jinx-unamused]

It's pretty simple, if someone isn't going the flavor of the month best build/best champion/best ANYTHING. It's very rarely due to ignorance, rather it's generally because they don't care to do so. The more the community acts as if there is some objectively correct way to play the game, the more riot is going to design their game in a way which has only a single viable ways to play the game.