It's unclear to me if this guy didn't learn enough or if it just wasn't hard enough. I do personally think that some courses are hard for the sake of being hard. If he learned the material stated in the syllabus and it was easy, then that's a really great thing and a tribute to the teaching.
Some courses are hard for the sake of being hard, because they are intended to filter out students who can't hack it. The degree is proof that you had the intelligence and determination to earn it.
When you're not awarding a degree anyway, that consideration is irrelevant, and the only requirement is to teach as clearly and effectively as you can.
