But does that apply to translated articles?
I am not a mod, so I can only give you my opinion.
As you say, in any reputable scientific journal, a simple translation would be plagiarism and wouldn't even being considered for publication. This is discussion forum though, not a scientific publication, and the same rules don't apply. As long as there is clear attribution to the author and a link to the original, I think that's ok. At least translating content (properly translating, not using machine translating) requires a bit of effort. There is certainly a place for translated content, but I will concede that the majority of these translated threads seem to fishing for merit.
So what is the default assumption then? That if something is not attributed then its reproduction in any context is an attempt to do this? I think that's too simplistic.
I concede you are probably right here, and I'm being over zealous. As discussed above, in a professional capacity I'm used to everything requiring full attribution, from a graph to a photo to a single statistic, but those rules are too strict to apply to the forum. It just doesn't sit right with me using someone else's content without at least mentioning their name.