I wonder if men (and it is almost always men), who get off on the intellectual masturbation of forensically dissecting the issue of prostitution, realise that to most women, they have the Internet version of creep stamped across their posts, which women are only too familiar with, having encountered it almost all their lives.
If anyone can point me to any other alternative source where punters are talking about their experience of prostitution, I'll take a look.
Meanwhile, we have an article from a photographer, an article in the Guardian, and a website devoted to their ratings system. Which sounds like a fairly balanced cross-section to me. Over half the men in the OP's link were married or in relationships. There was no stereotypical profile, certainly none that would fit the definition 'psychopath'. Just your ordinary, common or garden creep/rapist.
"More than half admitted that they either knew or believed that a majority of women in prostitution were lured, tricked or trafficked."
"One of the most interesting findings was that many believed men would "need" to rape if they could not pay for sex on demand. One told me, "Sometimes you might rape someone: you can go to a prostitute instead."
"many others admitted that they thought the women would be feeling "disgusted", "miserable", "dirty" and "scared". Ahmed said he thought the woman might feel "relief that I'm not going to kill her".