I found this blog post about the entitlement students feel to good grades. This is something I know a lot about since I am a long time student, a TA for the last 5 years and have taught a Humanities 1o1 course. I have never felt entitled to good grades because of the effort I put into my work. In fact, I put very little effort into classes and have still managed to pull off a 3.82 GPA. The reason is because I produce good work, I have very high standards for myself and I am generally good at what I do. Of course effort is a huge part of that (and maybe I would have a 4.0 if I put in the effort I know I should), but it is certainly not the only part. I know it is frustrating when you put effort and time into something and your grade doesn't match up to what you feel you deserve, and I'm sorry but we cannot all be the best at something and some people will also know more than you do, and if grades are given by quality of work that means that sometimes those people will get higher grades. That is why a lot of us study what we happen to be good at. I'm good at analyzing and writing papers, so that's what I do and I'm getting better the more I do it and I often get As as a result, but sometimes I don't. It happens.
I get frustrated with students who ask directly for As, or who whine and complain about not getting an A on a paper. However, I do feel bad for them when I know that they need an A to keep their scholarship, and I'm all about free money, so I generally give in. But some students have such a snarky attitude about it, as if they were really entitled simply for showing up and wasting my time with a crappy paper that I am forced to grade.