I agree with that, it has happened to me in the past where I wouldn't have found the lady as attractive as I had hoped but due to time constraints I went ahead with the appointment anyway.
Some I have not reviewed as it was my own fault and I still ended up not really enjoying the encounter, others I just put fairly attractive or Neither Attractive nor Unattractive.
I've only ever reviewed 1 lady where I said she was unattractive but that was a massage service which I don't really consider a sexual encounter so looks wouldn't put me off going ahead with the service although they are a bonus..