From a teacher's perspective.
Many student have absolutely no idea what the attainment levels are. They sort of assume that the best in class is an A grade student. So we have to spend time explaining and illustrating what an A grade (and all other grades) really is.
Every set of test results get shared around a class / across classes in less time than it take to blink - they all know who came top, almost before the last paper is handed back.
Over the last decade or so the idea of being successful with less than an A grade has diminished. So the student who works hard and achieves a C is discounted by many. Yet that C grade will get that student tot he next level of education - if they look in the right places, modify their expectations.
When I started teaching I was praised for the atmosphere of trust in my classes. All students knew each others attainments and goals and would happily work in pairs I set, matching strength and weaknesses as well as matched pairs. Later students would be shocked at that practice, would grumble at being asked to work in set pairs, parents would complain, Ofsted frowned upon it. Oddly attainment and student satisfaction dropped - OK, maybe not so odd.
Nowadays many parents and teachers were all taught that grades, results, goals etc are all secret, confidential. They cannot conceive of a reason for anyone else to know their business. They have no experience of valuing 'lesser' achievement, nurturing it, celebrating the individual, not the grade.
As far as I can see, and this thread confirms it no one is happier for that change, far from it!