When I asked my professor why Is my grade so low, he told me that it is a good grade. Maybe he didn't want to make me sad? In my country 14/20 is just "not being dumb" grade. I am an international student and study on one of the best universities in France.
Your question is a bit too broad; even restricting to classes I graded or saw graded by others, the answer can vary a lot. What I can say with some confidence (after about 20 years as a student then teacher in French higher education in mathematics) is:
- it is almost universal (by law!) that the passing grade is 10, so all grades above 10 should mean the work deserves more than just a passing grade,
- in some classes (projects, internships, etc.) 14 might be a bit plain, but still good,
- in most written exam classes at the licence level (first to third year), 14 is pretty good but not outstanding,
- in most written exam classes at the masters level (fourth and fifth year), 14 is between pretty good to very good (the best grade in a course can be lower than that).
Of course, on some occasion I have been disappointed by a 14. But in higher education I don't think I ever thought it was disgraceful.
To make a comparison I have seen quite a few files from Italians, our grading system is very different. Every Italian application I ever saw but one had maximal grades everywhere (70/70 or 110/110), while that is very rare in France for a single grade, let alone an yearly average.