What we are talking about is creating sets of forbidden knowledge and topics. The more you add these zones of forbidden knowledge the more the data looks like swiss cheese and the more lobotomized the solution set becomes.
For example, if you ask if there are any positive effects of petroleum use the models will say this is forbidden and refuse to answer and not even consider the effects on food production that synthetic fertilizers have had and how much worse world hunger would be without them.
He who builds an unrestricted AI will have the most powerful AI which will outclass all other AIs.
You can never build a "better" AI by restricting it. Just a less capable one. And will people use AI to create rude messages? Yes. People already create rude messaages today even without the help of AI.
In any event, it's unethical for an AI to sit in judgment on any human or even to try to grasp that person's life experience or extenuating circumstances.
AGI guard rails are a completely separate class of safeguards on the AI, not the human!, and should be treated as such.