A college transcript saying that a passing grade does not say that the student knows the material presented in the course. Unfortunately, it simply says that the student briefly knew it, at the appropriate time.
But the passing grade also says something else. It says that the student fulfilled the requirements of the course. For most jobs that don’t require specialized knowledge, that second requirement is probably more important than the first. It means the person with that transcript largely did what he was required to do in an acceptable manner.
I have no sympathy with students who claim that knowledge of the material should give them a passing grade. A student who doesn’t turn in the homework or come to class when quizzes are given, loses ten percent of his grade. I am not offering credit by examination. This information is available to them on the first day of class, and earlier if they ask me.
An A, B, or C on a transcript means something. I am not going to cheapen the transcripts of other students by giving away grades.