Would anyone mind if their job was advertised for anyone to take for free?
Yeah, I suppose if I was a paid adjunct this would bother me. My understanding is adjuncts get paid very little, and usually have something else going on that makes the bulk of their income. Am I wrong here?
who would put their children into the care of someone who is working for free?
It sounds to me like these people would be working mainly with grad students, maybe outside of a few lectures to undergrads. Grad students shouldn't be "children" anymore, at least I would hope not.
Maybe I'm biased, because several on my thesis committee were not paid through the University (two weren't even from the U.S.). There were some professors in the department (well mainly one) who had a problem with this. He was annoyed because he felt I could get nowhere without his support (he basically told me as much), and I didn't like his style and didn't want him on my committee. But, luckily for me, I had options.
I think the end result of my research was much better because we had direct input from private, government, and academic professionals who worked with me out of interest in the research and not monetary gain. Well, authorship was maybe another motivator, but I digress. On a side note, we did let that one professor review the paper before we submitted, so he still got to feel important.