To answer your question I think it's a crude and generalised analogy.
The therapist who harmed me did not set out to; of that I am sure. Harm occurred as a result of his inexperience, misplaced self-assurance, lack of appropriate training and blindness to his own limitations. He wasn't able to provide the therapy he claimed to provide.
I know from my subsequent therapeutic relationship that it is possible to provide emotional support and an appropriately-boundaried space where therapeutic work can happen. That is what I am paying for - the therapy.
The fact that I pay him for his time makes him no more of a prostitute than a dentist, lawyer or gardener, who are also paid for their time by the hour.