"Nobody can avoid being X, so therefore X is pervasive, and it is pointless to try to constrain X"
In this case, it's "everyone has bias, so being unbiased is possible, therefore all viewpoints are equally valid and should be presented as such".
You can substitute X with greed, violence, jealousy... any human failing, and it can be used as a method to justify poor behavior by appealing to epistemological or moral nihilism (all knowledge, morality). It's essentially the last refuge of people backed into a corner of epistemic closure and an attempt to avoid reconciling their worldview with reality but rejecting that there is any knowable basis for morality or truth.
"Nobody can avoid being X, so therefore X is pervasive, and it is pointless to try to constrain X"
That's not a nihilist. It's being defeatist. Giving up because you can't win is defeat. Giving up because there's really no point in the first place is nihilism.
>rejecting that there is any knowable basis for morality or truth.
Which is correct. There is no such thing as The Morality or The Truth or The Good.
They are but figments of our imagination, byproducts of a mind that's evolved to generate
patterns and see order in the chaos that is reality. Blame Plato's witchcraft.
The golden rule is so trivially easy, has been repeated in multiple cultural and historical contexts, and provides a reasonable basis for all moral philosophy. If you want to indulge epistemological nihilism then please turn in your laptop and cell phone, because you don't even want to know how many things they take for grant as "The Truth".
I don't understand what you mean by this. What exactly do you mean by nihilism in this context?