e.g. if a poster tells a victim of rape she should just have said no and should have taken control then it is, IMO, perfectly justifyable to call that poster whatever names one sees fit.
Or if a poster compares children with sn to serial killers it is, again, perfectly justified to make one's opinions of said poster perfectly known without needing to face the prospect of deletion for doing so.
If someone's views are so abhorrent why should they be afforded the right to claim victim status when they are labelled for those views, and a personal attack on that level is nothing more than that - a label.
So while I do agree that on the whole personal attacks are wrong, I think that there are exceptions to every rule and that perhaps some should be left, in certain circumstances.