Let's take the examples in question: I've never seen either Murray or Pinker come out of the gates swinging with poorly framed appeals to genetic determinism (if they make reference to such things at all it's almost always in response to criticism, and it never seems to be more than very light handed considered speculation). I've also never seen them lob insults, outright support mob justice, or make a targeted cherry-picked attempt to discredit a particular individual (admittedly I'm only so plugged in so it's possible I'm missing something). Yet their critics seem frequently guilty of this.
In other words, I don't think I'm holding them to a lower standard for having spoken first. Am I misunderstanding the argument? Or am I actually doing this and I'm just not aware of it?
Edit: Perhaps it's also worth stating that I do hold these two people in high regard which definitely lowers my defenses when it comes to quickly evaluating their various claims. Mainly based on how they have engaged in good faith. That said, I disagree with both of them a lot. Recently I've put a lot of effort into identifying a group of folks that I disagree with but respect, since it seems like almost nobody does that and it seems like a big problem that people only respect those they agree with.