Why must I be nice to people who are badly behaved?

Just disable direct messages. Problem solved.

We shall have sweet words which can wash out dirty words or even bad behaviours

It's not that complicated honestly. One of the reasons is to keep the community positive and decrease toxicity. From all online games there are, Chess has one of the most positive communities to be found. Having played 1500 games on Lichess I have seen only one person to say something negative after the game. Saying GG Ez which is really irritating.Aside from that i haven't seen any other type of negative behaviour playing chess at all. I have even been praised for good moves which is really rare in other communities. The chess community is one of the best and most positive communities there is out there and we should be grateful for it and keep it up.

If someone is mean report them. Someone threatened to hack me and typed the f word, I reported them, and now their account is closed. It's very simple.

@CoderBoy

" The chess community is one of the best and most positive communities there is out there"

I am not convinced of that. I would believe that lichess has a slightly higher ratio of positive to negative people compared to chess.com, for example.

But I am sure that there are more online chess jerks compared to - oh, I don't know, the online contract bridge, or knitting or banjo communities for example.

@ambrooks You're right but I don't think it's that broad. Lichess just bans negativity depending on how bad it is. Threatening to hack someone will get you banned instantly, but sharing a tournament password will get you timed out.

I did the second one once, but I got threatened by a 'hacker'. That's how I know.

I'm only talking about behaving badly which usually is referred to as being toxic or toxicity. Sharing your tournament password is breaking the TOS which is an other discussion. Threatening, cussing, ridiculing and etc can create a negative atmosphere. And it's true that there are better communities than chess community but I don't think think they're nearly as big as the chess community. As the community increases in size, the toxicity also increases and it encourages more toxicity on the other side like an endless cycle. When i said chess community is positive I simply said it based on my own experience with other online MOBA and shooting games.