The user does not want to be insulted, offended, triggered, or otherwise unsettled by a chatbot.
The bot employs insensitive dialogue that can insult, offend, cause the user to be triggered, or otherwise unsettled.
Whether through inappropriate jokes, ugly associations, dubious assumptions, or just thoughtlessness in choice of words, a pleasant experience with a bot can turn into an awful one. In general, the cause is a designer who assumes all users share their worldview, their prejudices, and their sense of humour.
Does this mean that bot dialogue should be bland and unremarkable in order to be safely inoffensive? Absolutely not. Brilliant copy can be witty, sharp, and inclusive. It does mean, however, that copywriting such dialogue should not be seen as finessing an otherwise effective product. As far as the user is concerned, the dialogue is the product.