I write reviews so that other punters can make decisions on who to spend their money on. From that point of view negative reviews are just as, if not more, important than positive ones. I also read reviews by other punters so I can do the same, and I have a fair idea which are the reliable ones.
I know this is an underground business, but why should we give money to escorts who don't make an effort, or who make false claims about the services they provide to clients.
As has being said many times before, it's in everybodys interest to filter out the time wasters - on both sides.
Reviewers should be able to write as many reviews as they want to, positive or negative. Everybody should use their own judgement, when it comes to interpreting them.