Chat filter is broken. Players willingly turn off chat filter...
People turning off the Mature Language Filter isn't an indicator that it's broken. It's an indicator that those people don't care for the filter.
...then report players for chat that they willingly subject themselves to. It's not an excuse to be toxic but it is fundamentally flawed.
Well, here's the thing; the Mature Language Filter is there for people who have lighter/different sensibilities in regards to swearing and curse words. It filters out and censors swearing, but it doesn't do the same for flame and abusive language.
Frankly, I don't see how you can 1. determine who voluntarily turns off the Mature Language Filter and 2. leverage that as an explanation for people getting punished.
You don't know who reports who, and you don't know who has their Mature Language Filter on or off; and I'd reckon that there are just as many people out there with it on who report misbehavior as there are those who have it turned off that do the same.
At the end of the day, the Mature Language Filter isn't flawed; you're simply misunderstanding its purpose.
Players should only be restricted if they manipulate chat to bypass the filter, and are reported. Otherwise how can any chat ban be justified. You willingly turned off your filter and that action may as well say "im ok with seeing anything in the chat"
Well, again, read above; the Mature Language Filter censors cursing and swearing, but it doesn't censor abusive language, flaming, etc;
And while, yes, the general idea being sent when someone turns off the Mature Language Filter is "I'm okay with seeing swearing in chat", it doesn't automatically translate to "I want chat to be a complete toxic cesspool".
And, regardless of what you believe, the rules take precedence over the existence of a Mature Language Filter, and punishments are justified by the rules. You should check out the Code of Conduct and the Summoner's Code for the rough details of the rules.
If you have filter disabled, any chat related report should be instantly thrown out.
No. The Mature Language Filter does not supercede the rules you agreed to, and it absolutely should not deny players the ability to report people for breaking those rules.