I used to teach political science, history, and American studies at the college/university level. And while I had some wonderfully insightful and smart students, I would get my fair share of slackers and complainers — mostly around midterms. I'm sure you've guessed that the most common complaint was about grades. The complaints varied, and sometimes a student made a compelling case for a grade adjustment, but for the overwhelming majority of students, the grade given was the grade earned. For those who felt that their grade was a personal reflection of what I thought of them as a person, it was very difficult to have a conversation about the quality of their work. Even when I used an "A" student's exam or paper as a point of comparison, it would fall on deaf ears. Often, I would get the "But I'm and 'A' student!" defense (read: "You're obviously a horrible teacher and have no idea how brilliant I am!"), but that was usually a parting shot made on the way out to drop the class.
J (AKA "My Beautiful Wife") wrote about a practice at some middle schools where students can bring items into the classroom for "extra credit." For example, if a certain class didn't have enough paper towels, a student could earn extra credit points for going to Target and buying a 24 pack of paper towels for $8.99 (or whatever the sale price is). You see where this is going, right? A "C" student in "Intro to English Lit" spends $300 on "classroom supplies," but still doesn't really know how to write an essay or read a novel, but still gets an "A" or maybe a "B+" because of "extra credit" points.
If you want to see what a sense of entitlement can wrought, check out some teacher horror stories at Rate Your Students.