[-pixie]

Whilst I agree that nobody is "born thick", I don't think you can blame the teachers for certain pupils not learning to standard. If certain groups don't see education as having street cred, then to me that indicates a problem in the home. The parents should be taking a more active role in their childs education, instead of blaming the school.
Teachers and their power in the classroom are that limited now that there isn't a great deal they can do to rectify the situation. School should not be expected to compensate for anybodys situation at home.