The thing is, this is still tying culture to race. If there is no racial essentialism to the traits you describe, then there’s no reason to say that some goblin cultures / sub-cultures do understand the concept of property - and disagree with what they understand to be stealing. Etc.

I don’t see how this just doesn’t create nuance, which is fantastic

Sure, it adds nuance - and if that’s all you care about then you’re all set. But it doesn’t address The Problem, which is painting “races” as monoliths with essential characteristics. Just because you can explain why All X Are Evil, doesn’t solve for it being boring/lame/tending-toward-offensive that they all are. Seems like we dealt with this in other contexts, why not include it in lore?

Think of it more as culture tied to community. A village of goblins is going to behave one way, but a goblin raised in a human city will behave another way. Yes there are characteristics that are generally associated with a species (I shy away from “races” generally, too loaded of a word). But that’s just because those species generally form their own communities. Are all goblins like this? Of course not. Are all goblins that the small town cleric has met like this? Yes.

It’s not really that different from a native Californian thinking a native New Yorker is rude and interrupts all of the time, and the New Yorker thinking the Californian doesn’t engage in conversation, simply because their conversational speeds differ enough that it creates underlying tension. In that example, did I paint all New Yorkers as rapid speakers? Yes. Is it generally true of native New Yorkers? You tell me.

There will always be generalizations, and there will always be nuance that disproves the generalization. When telling a story the secret is knowing WHY the generalization exists and how the character relates to it.