Thankfully you don't have to pay the teachers here.  You're welcome to do without their lessons & therefore owe them nothing.  It's the same kind of free enterprise that exists in all businesses.  The fact that you don't want to use them doesn't make it unjust.  Neither does the fact that they want to be paid for their services.

As a certified teacher, I choose to teach on italki due to health reasons.  I was running my own English Language School but had to stop because I have thyroid problems and severe migraine headaches that sometimes leave me bedridden for days.  I enjoy the flexibility italki gives me.  If I am feeling poorly, I can still help my students, but I don't have to waste energy getting ready and driving somewhere.  I am slowly building a consistant student base, and getting to work with people from many countries.  The joy I get from teaching and the new friends I have made are worth the $20/hour salary cut I took by moving online.

do you know there is a job called online teacher ...?they wanna earn  money on line ,and there is no wrong with that .