I encountered it myself by now in a different way. I mean i get it of course. The NN is not meant to be used as a chat, but that wasn't even directly the problem. Someone assumed that i meant something i absolutely did not even meant to say. Got asked to stop and i did. Someone else however replied to it and build up on a joke i made which in the end received the kick at first for.

Again. Yes. NN is not for casual chats, but it does not need to be taken dead serious all the time. I am playing a game and we are social people. Making a joke here and there is to lighten the mood and if no one else is actually asking or writing anything for hours, i absolutely do not see a harm in it.
I do use the chat often for the intended use to get information on what to do or if i know something myself i even reply. Even if it is a question or discussion regarding other games and their mechanics to understand something or similar things.

Later on i did say that it was kind of a over the top reaction, but also unfair that i got banned that someone else made a joke again, where i already stopped saying something that could be considered anything mean. To the joke the other person replied to me i merely answered: "You got what i meant."
And the "mentor" flipped.
Saying that it was a bit of a harsh reaction that i get kicked that someone else added up on the joke later on as i returned only resulted in threats and pulling others to their side even if they wrote that moment: "I don't even know what is going on."

It's toxic behavior. Nothing else. IF the joke i made was that horrible, since it was a in game situation in a quest i joked about.. either some people never had a childhood themselves to understand what i was saying, or it was a simple case of a power trip. Even some of my friends in the game were reading the chat, laughed (which i am still kind of doing about even now, since it is just ridiculous to react this way) and told me: "Yupp. That's NN for you. This is the exact reason why i don't join it. You only get these elitists, power-abusive and narcissists who get off to this if they can do play their powers like this.

And i say it again. Yes. Casual chat is not meant for the NN, but a social word here and there should not be treated like someone just killed the president.

To the person who did it, in case you are reading this. I told you in the NN and i say it here again. I take it still on the chin. There is no "dignity" lost from my side as you claimed it would be, it is you who kind of lost your way on this whole thing. Still i bare you no real ill will. Have a great day.

And no. I am not a "sex creep" as you insulted me with, just because i made a joke about skirts on men.