The key word in your post/question is appears.
If someone "appears" to be something and another "assumes" that individual to be what it appears and he/she criticizes that person based solely on appearance or assumption, I would consider that dead wrong.
For example there have been lots of eye candy and beautiful women casted for Survivor, and many were not promiscuous in any way. Now even if men who had no control over their libidos may be drooling all over them, for someone to label those women "Hos" or "sluts" based on appearance is wrong.
Conversely you did have players such as Perv-ati and Sarah (Survivor 4) who skanked their way through the game. If those castaways are labeled "floosies" or Hos" then I feel their promiscuous actions held them accountable for their criticism.