I make no claim to the overall value of LLMs. I'm just pointing out that your analogy is a fallacy. The fact that group A does a small bad thing is not a justification for allowing group B to do a large bad thing. That is true regardless of whether group B does there non-bad things.
It may be the case that the non-bad things B does outweigh the bad things. That would be an argument in favor of B. The another group doing bad things has no bearing on the justification for B itself.
It may be the case that the non-bad things B does outweigh the bad things. That would be an argument in favor of B. The another group doing bad things has no bearing on the justification for B itself.