I read the article. Good read. One thing I'll say is while I don't really regard a voluntary agreement between two parties to be exploitative in the first place.. even if it was, I'm not sure it's really a positive thing to have strict controls over 457 exploitation to the point of foreign workers just not being hired here, and then being exploited even more in their original countries instead. If you think low pay is exploitative, I think making sure these people aren't low paid in general should be the aim rather than just "not in my neighbourhood".