Hello Captain
Most often the chat ban is caused by these two things
You said something bad several times or you said something very very rude once, especially if this rude statement related to a person sister, mother or brother.
Chat ban is not limiting your ability to play - you can still attack NPCs, players or craft or travel. You just cannot talk to others.
If you know what case chat was withdrawn for - you can apologize to that player in tribunal and if it is accepted the ban will be lifted.
Be nice to others is on the purchase page and this is always going to be this way.
We are all adults (above 18+) and can just guess what is ok or not ok to say to a stranger with a gun in an indian territory during wild west times
There is also a list of acceptable age of sail curses that can be directed to other Captains.