That's precisely what a pimp does
I am not certain that I agree with that harsh word. There are many groups who write quietly with a sense of responsibility. Sometimes there is an urge to write and it is difficult to find an outlet. At the same time, as Lavinia has said, it is a source of income, especially for people like me, who are looking for research fees. I do not have the ability to start and run a company on my own.
Also I know now that most of the flashy companies in this trade are not as genuine as they say. If you read some of the evidences provided by WritersBeware you will know this fact. Some unknown companies, who might not like to get known beyond a certain limit, could be very helpful. They remain so, because they could be a bit ashamed of writing student essays and are doing it due to circumstances. There could be part time tutors, who need a second income and I know many of them. There are doctorates who cannot get a placement immediately. All of them are sincere. They do not want this to be a life time job.