I think you got your answer early in the thread.
> Is it wrong to be against a rational discussion of (.+)\?
Yes, it is.
The rest is the discussion why - in particular by pointing out that rational discussion does not automatically imply that abhorrent conclusions will be reached or accepted. The primary thing about rational discussion is that some (or all) participants may be wrong. It's also the difference between discussion and shouting through each other.
I'd note that I'm asking question, and I keep getting "we don't need to discuss that" responses.