Not whether it is a terrible thing to say. But whether saying it should be banned.
Here’s a super simple example.
Jerk: “I think we should shoot immigrants”
Non-jerk: “that’s a bad idea because immigrants have souls”
Former-jerk: “good point. I changed my mind and no longer think shooting immigrants is a good idea. In fact, I will now dedicate my life to helping the needy and everyone who reads this thread should as well.”
It would be bad to ban a thread such as the one above.
You're gonna have to provide a context in which this wouldn't be a terrible and unacceptable thing to say, cause I can't think of one.