Let me attempt to answer your question,ie,why louwai are 'sucked in' by such ropey outfits.
Maybe said foreigners had neglected googling the net to unearth valuable information re their prospective employers before venturing forth and/or committing themselves.
Or perhaps it was a case of Hobson's choice for said louwai.Even so,going back to your homeland,or not leaving it in the first place,would have been best if your potential employer had been red-flagged by posters on the net.
In a word,do your homework first.Or you may live to regret not having done so!