"If every student receives an F for a 40% correct (and they all only get 40% correct), a curve normalizes that. Students who understand the material as it was presented and tested better than others receive a higher grade."

If every one in the class was lazy to study/prepare for the exam and every one ended up getting less than 40% correct, then they all deserve to get F. Normalizing with a curve means, it's possible that someone who got only 39% in that exam in a class full of lazy folks who all scored much less than him, can earn a A or A+ ! Compare this to similar class/exam taken by different set of students (all brilliant) at a different time or place, who all worked hard and scored above 80% but still some of them could get B or C's due to curve grading. Wouldn't it be unfair to the 80% scorer who got a C whereas some one who scored a 39% on the same subject got A+ due to circumstances (time and peers he took the exam with) !! How is that fair at all?