> The whole subthread is nasty
> regardless of how others are behaving.
If you disagree with any of the opinions in the thread, please comment. Labeling them as 'nasty', or implying bad behavior without pointing it out is something that should be defended.
If the implicit assumption is something along the lines of "people I disapprove of deserve what's coming to them", then again, that interpretation is entirely yours.
It's not at all required to mention if you disapprove of something when chastising someone for abuse. It undermines the point. Makes it sound like some unfortunate technicality or point of honour.
If you have a problem with the content of the thread, mention it, and defend that opinion. Otherwise, don't mention it. Flinging labels from above helps nothing.