"exploited" is a matter of perspective. To an onlooker who has lived their whole life in a first world country, seeing people work for $x - (less-significantlyLess) [where $x is what is "typical" for the job] can be seen as bad/wrong/sad etc...
I have spent time working in very poor parts of Mexico and Manila. Crime is rampant, I feared for my life at times. Polution/open sewage made my eyes burn. By the end of my job there (helping doing on site server data migration for a financial institution) I was willing to pay/do anything to get out.
We take many things for granted that foreign workers might consider "Perks of the job". $1 has far more buying power in Manila than a place like the Bay area, but I would live in the Bay over Manila, essentially taking a wage cut.
This does not condone the wage discrepancy btwn foreign/domestic workers, but offers a potential explanation why a person would happily take an apparent "pay cut", and even be better off.