I'd seen the "scandal" and a few articles referenced around the internet and only just now actually read the article... I'm sure it's a combination of personally reading a lot about manufacturing and labor standards (mostly clothing or electronics, but still), living in rural China*, and therefore having a more realistic understanding on life/standards there than most Americans do, but I expected something more shocking. Instead, what I'm gathering is that consumers have been making unrealistic assumptions about where their goods come from.
*which is obviously not Korea, but the gap between what I had though of as standard (in terms of safety, comfort, legality, decency, health, I could go on forever) in the modern world and things that were seen as perfectly acceptable across the globe were ...illuminating. Based on my observations, and the differences between what I expected/assumed vs what I saw, nothing I'm seeing or reading about the Korean masks is shocking to me. There is slave labor entrenched in goods as ubiquitous as chocolate, seafood, and coffee (which I assume is commonly known, but maybe not?). I expect you could find the same thing in nearly any manufacturing line if you looked. We just prefer not to look at it. The success of most brands depends upon it, all the way from Wal-Mart to random indie company who purchases their packaging from the most cost-effective source.
Edit: Sorry it's kind of wordy, I'm trying to write how I'm thinking, and it turns out that I think in a jumble.