Writing plays isn't easy, and in most cases with which I'm familiar, it isn't a requirement for an English degree, The stilted dialogue and lack of depth make him an awful playwright, but his grammar and syntax appear to be at least competent, so I'd guess he could write acceptable, maybe even pretty good, papers and essays.
This is why he was going to graduate. Most liberal arts professors are relativists, afraid to pass judgment on content lest they appear too judgmental. So they grade the grammar. This particular student was smart enough to have figured out the language without understanding anything about the nuances of the culture that the language is a part of. I'd be curious to know what his GPA was. I suspect it was in the mid 3's, which would shed quite a light on the nature of today's higher education system.