Grading sucks because it is too easy, and creates a "wait to fail" mentality for the teacher.
Every student has things to improve, learn, get curious about. The A has so much finality, the F more.
The worst part is that letter grading is a near total failure at determining future competency, that is, in areas other than where one is letter graded.
Grade the below. That's what it feels like for me to grade writing.