I think it's more the fact that it was an advertisment on a JOB board. Why advertise when you could walk into any flight school and get a body to fill the seat?
It still sets a bad example for any employer to want a co-pilot/body and not pay them. But as long as people want to give up a paying job for "jet" time more power to them. I just hate hearing people complain about their pay when we have positions like this that get filled in no time flat.
Just my $.02