I much prefer that I be ranked on my grades objectively, than I be ranked on something else like 'he attended oxford', because the second is likely due to the wealth and influence of my parents.
When a professor gets to subjectively evaluate a student, who do you think will fare better, the student who speaks like him, also plays golf and whose parents attend the same country club, or the other ghetto dressing slang talking student?
An exam is hard and objective. It speaks the truth, because it's judgment is cold and not affected by any preconceptions.
Excellence should always be as objectively graded as possible, because humans have too many biases.
That's what standardized tests, like bar exams and medical licensing exams, are for.
Medicine is different because it's about a lot of knowledge and being able to product that knowledge when required (same with lawyering). Programming is different in that you look up the information, the body of relevant info often changes, paradigms change constantly. You can't standardize this field (yet).