Was he making a relevant point besides that the West/US has done bad things too?

I guess I inferred that he was pointing out the futility of looking for a place to move factories that is untarnished in this regard. If that was his point, he's right. I can't really think of any place to move the factories to that wouldn't just be kind of pointless. I mean, pretty much everyone uses deadly force against muslims. (Maybe someplace where they don't have muslims? We might be able to move there?)

In any case, I should probably just let him, (or her), outline what their own point was.

If you want to dispense justice, then I should remind you that Lady Justice is blindfolded for a reason. If you want to selectively punish China but not others then it's not justice, those who are punished immediately see that it has nothing to do with their bad behaviour.

So then we might as well just leave the factories in China then?