Why have a mature filter

That's why we have an option to turn it off if one so desires, the mature filter is just on by default.

You can curse all you want if someone doesn't find it offensive

WHY IS VERBAL ABUSE PUNISHABLE IF THERE IS A MUTE BUTTON/LANGUAGE FILTER?

Players shouldn't need to rely on features like the mute button or language filter to engage with other players in positive ways. When a player verbally abuses another player and forces him to use the mute button, they have already created a negative experience for that player.

Please, stop making excuses to be toxic.

Edit: Looking back, I see that you've been trying to justify your toxicity for a while now and have simply chosen to ignore all warnings and punishments. I hope you learned something from your permaban so you can become a positive person, whether you continue with LoL on another account or not.

Its not about cursing, its about how you curse. "That was fucking awesome" is a lot different than "You fucking suck". The filter is there for those that prefer not to experience any form of profanity/parents can require their children have it on etc.. Just because I have my filter off, does not mean I would tolerate verbal abuse.