Should not schools eliminate "D" grades?

Should not schools eliminate "D" grades.One reason is because eliminating the grade "D" would cause the students to freak out cause they wouldn't be able to know if they are about to pass or fail. Another reason is a "D" interacts in a way for the student to understand that he/she is spreading themselves too much or are starting to get lazy. Additionally, a "D" can help a student pass high school if they are struggling in school. In conclusion, that is the reason as to why there should be a grade "D".