But the kind of behavior I'm seeing now is a bit saddening. I remember when HN guidelines said something to the effect of "Instead of saying 'C++ was created after C, idiot' you can shorten it to 'C++ was created after C'". But I see posts in the tone of yours which say something like "The left has isolated incidents of violence by deranged people, blasted by leaders on the left while the right has much more dangerous and common events which seem to be supported by the leadership. To put these two together is disingenuous and could only be done by a fascist.", where that last sentence could just be left off.
The issue is assuming the absolute worst of everyone you talk to online that doesn't hold your opinion. Maybe the poster just has ignorant friends/family and really doesn't know any better. Maybe they have opinions right now that they're going to be really embarrassed about in 10-20 years. But if you immediately group them together with people like Hitler (didn't this used to kill the thread?) then you give up any hope of educating them (or, more importantly, other people on the fence who are reading the exchange). So I have to wonder what is even the utility of such posts except to signal to others which camp you're in.