I am wondering if there is a somewhat murky line (at times) between scam, and incapable?
I think that, for a customer purchasing an essay, the two are intertwined: a capable, talented writer or group of writers can build their business by writing quality works and charging an appropriate amount for them. Incapable writers can't get by with writing crappy essays, so they resort to scamming, by undercutting competition's prices, producing a poor paper, and then forcing the customer to maneuverer through numerous paths in order to get any sort of refund or service.
When it comes to the company's writers, though, I don't think incompetence can explain why so many services are accused of unfairly fining their employees or refusing to pay. That's just greed and a scam.