I think he is trying to say that what this journalist is getting paid could be better or worse than other factories, but there's no way to tell reading this article. The author expects the reader to compare it to dollars as stated with the $4 wage. How many Yuan is that, and how many Yuan is a good living over there? I have a friend living in Shenzhen and he gets by on like $0.25 a day, living like a westerner.
And of course you are going to get reprimanded if you don't do your job correctly, e.g. too much oil or inaccurate placement. And of course a new employee won't be good at it at first.
Personally, the most atrocious thing I've read in the whole article is that dirty sheets is commonplace. And frankly, that is common in China.