IMO there's zero correlation between grades and knowledge/ability to apply knowledge. So many peers in college cheated. My boss at my last job (while I was doing OMSCS part-time) suggested that I cheat on a project. In undergrad I saw peers looking up (and successfully finding) answer sheets online _while in class_.
I even knew those who did the work honestly, received high marks, and then couldn't actually write reasonable code. In my capstone project one of my teammates ask me if his code needed to compile or not. Another couldn't implement a function that translates ASCII letters -> numbers without a lookup table.
Anyway, all of this to say, maybe we just shouldn't care about grades as much.