not that those rating systems can't be gamed, but yeah, this would definitely be better than the current situation of criminalized prostitution. esp if prostitutes could leave reviews of clients. i imagine there'd be less scamming, violence, and disease transmission on both sides of that sort of transaction if there were reputable rating services that let prostitutes and clients vet one another. it would also lessen the value of pimps/madames/etc, thus making it easier for prostitutes to work independently, which would hopefully lessen the prevalence of sex trafficking and sexual exploitation.
so yeah, weird, but in a good "we finally got rid of a relic of our prudish past" sort of way.