Riot you want the Toxic Community to Stop?
 

Then teach the community how to play the game.

Riot should create videos that teach the community basic aspects of the game. What this will do is give the player base a foundation on what good and bad play is. If the community as a whole agrees on something that is considered bad play then people playing bad will not have an excuse for playing badly, and less back and forth raging will happen. This is because the bickering can simply be solved with a "watch video such and such basics" and nothing else would have to be said.
If the person tries to make a retort about watching the video he is truly a toxic player. Which would make it much easier to find and identify toxic players because they are unwilling to change, learn and adapt to the game.

ARTS or MOBAS in general have a high learning cap. Most "common" knowledge for more dedicated players is not common knowledge for the majority of the player base.

A few examples would be a video on how important CS and gold is. A lot of people treat Summoners Rift as a death match. I have even had people tell me gold dose not matter its all about 'skill.' Yet that is part of the foundation of the game and players don't even know that. They treat this game as a fighter such as Street Fighter yet it is more akin to a Real Time Strategy.
Another example is chasing. People chase to the ends of the world to get that kill. People would rather lose xp/gold for a kill than just play safe and back off. They don't understand that by pushing the person out of lane they are losing gold and xp and it was a success. They don't understand that if you forced someone to blow a summoner spell that you did a good thing. You can try again with a greater chance of success.

Team composition might be a little more in the advanced area but it is something that seems to be more crucial than Dota. A bad team comp means you lost at champion select. There should be some sort of foundation on what a good team composition is and isn't. Such as having a team full team of Assassins is terrible compared to a well balanced team that synergies with each other,

Perfect example of good synergy, Nocturne Ult + Shen = amazing.

This game is more knowledge based that most other video games. I really think Riot should start teaching the community how to play the game on a basic level. If they wanted to Riot could encourage pros to teach the community at a competitive level. For NA it would actually help the Pro NA team maybe win a few tourneys? (jk jk or am I?)
I am not saying Riot knows best, but they are better than the average person simply because they created the game. They test and figure out most aspects of the game because not only do they make it they enjoy playing the game.



TL: DR version

Riot needs to teach their player base how to play the game even if its just the basics to help curb the toxic player base.

Ex: 20 cs = 1 kill.
Ex2: Play safe and farm when at a disadvantage and force the other team to make mistakes.

I will now be bumping this will simple facts on how to play champions, yes I am no expert its why I said simple facts.

Edit:

Someone posted a link to help players get out of ELO hell. http://eloheaven.enjin.com/
Haven't really checked it out but hopefully it helps.

if they really want it to stop, they need to include pre and post game chat in the Tribunal report. Most toxic behavior, players admitting to trolling/feeding, etc happens there and carries into the live game if people don't dodge.

Include that and the amount of toxic players removed will near double.

Your post, sir, needs a TL;DR version.

But my point is, have you ever seen a rank 2000+ rioter?

I'd support this, except for the fact that the lessons would need to be based around the current metagame (10-15 minute dragons, after Top has snowballed, farm to about 25 minutes, then mid for teamfight), while Riot says that they will change said metagame significantly in S3.

If i were in Riot's position, I would put some basic lessons.

Ex. CSing, popular warding locations, Spawn times and timers of various jungle creeps, a fast way to tell if you will survive a dive (maybe not, its somewhat complicated.)

Again no. Tribunal will not solve the toxic community.

Have you gone over to the Asia servers? They actually work as a team on a regular basis. They actually pick teams that have synergy are revolve around a particular team comp.

The Tribunal is not the answer. Changing the communities social interactions and goals is how to fix the toxic LoL community.

Also Maining a champion is another reason for this toxic community. There is no such thing as 'maining" a champion when you need to be good at many different champions in case you would be counter picking your self picking your "main" champion.

Phreak and Solcrushed are both plat / diamond.

Honestly, Riot needs to promote, advertise, and give free 'trials' from learntheleague.com. I'm sure Ciderhelm wouldn't be against this, and it would help people a lot.

If pre and post game chat were added, a lot of the frustrating involving people admitting to troll picks (jungle Soraka) to force people to dodge or claims of intentional feeding, something that's typically hard to prove in game unless they admit to it in chat which many aren't, and other behaviors like that would be able to actually be punished. Due to pre and post game chat not being included in the logs, you get a lot of the toxic players abusing that fact. Trolling typically doesn't start in game. It starts more often at champion select. Last pick saying "MID OR FEED NOOBS!!!" for example after a mid is already locked. They then go on to feed like they said in the match. The problem is that if they don't admit to it in the in game chat, it's hard to prove since some people are just bad or have a bad game.

Uneducated players or "bad" players will eventually learn the ropes. However, players who go out of their way to ruin the game and experience for others need to be removed and are more of a problem. Pre and post game chat is a large blind spot right now that without, saves people that need to be banned from being banned.

They don't need to get 2000+

1700 would be good enough to teach people basic concepts like CSing, when to and when not to tower dive.

Tribunal is not the solution.

People do the MID OR FEED stuff because they "main" roles. No one should ever "main" roles in this game.

You can have your best roles but then you should be good at all roles to better understand how each role is played so you can counter play it.

The Tribunal also does nothing but get people paranoid about bans and creates a community fearful of communicating.

If you teach people how to play its a start on how to get the community focused on improving their own play as well as their team play.