Just like all words that become popular people just throw it around without knowing the meaning.

Let's look at the majority of the league communities favorite word to use, Toxic.

I always found that word stupid when used to describe a person anyway because you are still insulting someone but that is a whole different discussion

What I find while playing league people use toxic when they should probably use the word truthful.

What do I mean by this? i'll tell you.

Example: "Player A is a top laner who does not have his teleport up and has no idea where the enemy top laner is, he pings to his bot lane Players B & C and informs them that his opponent is mia and he has no TP.

Players B & C engage in a fight with the enemy bot lane and the enemy top laner starts teleporting in. Instead of running away they continued the fight and gave the enemy top lane a double kill.

Player A will then ask, 'Why would you ignore my pings you just fed my lane opponent.'

Players B&C will then say 'Stop being toxic''

Whenever someone who is approached with a question or some information they do not want to hear. They believe that is someone being toxic to them.

"what the fuck are you doing you moron?" <-- toxic "you're autistic shut up" <--- toxic

"maybe instead of rushing that triforce you should focus on going tank so you won't get killed so much" <--- not toxic "why are you building sunfire against diana jungle and rumble?" <--- not toxic

tl;dr The truth =/= toxic behavior.