Mturk is great because it is a service supported buy a great company. You know that if you work, you will receive your money. It is hard to trust in a company that nobody knows where you could eventually works for free
I don't agree with anything you've said. It's almost the same as slave labor, you can't ever think to support yourself doing work like that.
Companies are just leeching of off low-skilled labor and I know that some people really do try to make a living out of it.
Sure, they will pay you for the work you've done, but the rates they're offering are just not worth it.