"It's a combination of poverty and racial segregation, added to cultural differences, that all makes it tough for suburban teachers to figure out the black and Latino cultures."
The “cultural differences” is probably the biggie here. Such differences as respect for teachers and education, the attitude toward crime, etc.
Yes. When you read about parents coming into the classroom and beating up the teacher for some perceived affront to their child, it's easy to see how the school environment has changed.