Allow setup of least passing grade for each grading standard. Just as a range of percentages are tied to a certain grade, a grade/range of grades should be tied a boolean status - pass or fail.
Example UI for setup of least passing grade.
All grades below the selected one should be considered a failing grade and the ones above (including the selected one) should be considered a passing grade. Depending on the assigned grade, each student can then have a status "passed: true/false" for each assignment.
This status could then be used throughout the system to trigger feedback to students about "revise and resubmit" , new attempts on a quiz  or perhaps even an aggregated status for assignment groups (example: 7 points to pass, all quizzes must be passed) .
Example UI of assigning new due date for failing students.
Example UI of allowing attempts until passing for a quiz.
Example indicator of students passing/failing an assignment group.
To maintain consistancy, when using points or percent for Display grade as one should be able to simply specify a number for least passing score (Complete/Incomplete is self-explanatory).
Example input for least passing score.
Perhaps some of you see even more use cases for this status? For be, the biggest improvement would be to more easily manage students who need to revise a submission. For students, I'm sure they would appreciate a clear indicator of pass/fail even when using just points/percentage and not letter grades or complete/incomplete.