I wondered about this too, especially as it was only my 2nd review, which I posted late 2015 for a lady I'd seen in July 2014. What prompted me to hit 'post' was the lack of reviews and other info about her here, and her somewhat lacklustre service at the price charged.
Any info is better than no info I reckoned, and the comments the review got seemed to back up my experience, which must surely benefit the community as a whole, especially if the rating is negative or neutral. Positive reviews probably have a shorter shelf life though.