I strongly believe that everyone--teacher, student, artist engineer--needs a record of how awesome they are. When it comes to language, they need a record of what they can DO with the language, in case, you know, they have something to prove when someone has a job or a scholarship or some course credit they can offer.
Those people want to see the best work possible, and they want to be able to grasp what they're looking at--or listening to--even if they don't speak the language themselves. And portfolios based on proficiency give the students the language to need to explain what they can do and how well to even the "alingual" (shout out to Terry Osborn from our #FLANC50 keynote!).
