After 25 years of teaching freshmen to grad students, I expect the grade grubbing....but don't like it, and don't bend to it. My grades are established on the syllabus. It only took three hours after grades were posted this semester to get my first complaint.....I refuse to respond to questions over the break....Hey, I am supposed to be on break, as well. If they have a specific question, that's fine. I don't respond to "Prof, I got a C instead of a B, can you tell me why?"........if you don't know, maybe that explains WHY you got the lower grade.
It gets easier the longer you teach. I can only imagine how many students have failed to get into med school, engineering school, grad school, the military, their best job, (insert your vocational issues here) because I was mean and didn't "give them" the grade they needed (because, of course, it was ONLY me and my course that were blocking them).....and thank God that means I can drive over a bridge that won't fall down, might have an intelligent and well educated doctor, have knowledgeable administrators, and maybe even knowledgeable military officers BECAUSE I didn't pass along the students who didn't earn the grade.
Also, remember that you don't GIVE grades....the student EARNS them! Maybe if some of the CEO's had learned this lesson, our dear country wouldn't be in such dire straits.
(Stepping off of the soap box now!).