People often arrive at these answers artificially, based on assumptions and a limited world view. Perhaps this guy was cut off on the freeway by a female driver, but he ignores the thousands of times this has happened with a man behind the wheel. Although a person's intelligence and work ethic contribute to the majority of a student's success, this teacher ignores alternate causes of Bubba's failing grades. His family could be undergoing serious problems, such as divorce or separation, or Bubba could have an illness or disability that prevents him from achieving his best. The class also might be very hard, the textbooks weak, and the teacher too busy to recognize a cry for help.
Students here are very rude.
To categorize thousands of individuals into a group based on meeting two or three generates the classic stereotype fallacy.