Why SC/ST students are purposefully failed in examinations?

Question

when a SC/ST students are very brilliant, most schedule in school days and 1000 times having patience even though he is economically backward , why they are made to fail by teachers in college level . why don't the teachers think that they are the responsible for the national waste .

Answer 1

I have to disagree with your comments, as there are no quotas to fail students.  Most universities will dismiss a professor if all grades are high, such as all A or B grades, but certainly failure is not a requirement.  Think about MIT, if I pay tons of money to go, and I apply myself, I expect to pass, even if not with all A or B grades.  

Answer 2

because of some sc/st students the brilliant students lacks behind and dont get admissions due to quata system

a sc/st student scoring 55% gets admission in higher college where as a open category student scoring 85 has to search for many colleges for admissions

Answer 3

This is a serious allegation on all the teachers. Do you understand the meaning of what you are saying?