I understand, my school went through a time period where students that never graduated high school and lacked basic skills(reading/writting) were coming into the classroom.  It was an issue and we had to change entrance testing to ensure that these students were filtered out.

I believe that's human nature.  There's always people who think what you have to say is important and others who think they have better things to do.  That's the joy in teaching, finding a way to reach the tough crowd.