When we ask students to produce writing or speech to align with some kind of desired outcome written in a document somewhere, in the form of either an observable skill or a measurable content task, it inevitably results in a portion of the students feeling not as good as others in the class, or better than others.
When people are judged as measuring up or not, potential language learning communities are replaced by “those who can” and “those who can’t”. This gives the students who have been labeled in the general school environment over the years as not high achieving the idea that they are specifically “not good at languages” and most of them conclude that, because a teacher said it, that it is true.
The teacher’s “need” to “gather data” on “how the student is doing” (impossible with languages acc. to the research bc of the unconscious factor) may be honestly stated to the class, but it has a smell to it because it carries a subtext message to too many in the class that they won’t measure up.
Everybody can’t be an output star and yet anyone can learn a language. So, where collecting data on students in, say, a physics class may make sense, collecting data on children who are taking a language doesn’t make much sense. An entire book could be written on that last point because the acquisition process is unconscious. On the beach in CA once Krashen said to me, “What don’t they get about it being unconscious?”
Not everyone can learn physics, but given enough time and the will to do it with no shaming, no veiled judging, and no forced output to align with some out-of-touch-with-the-research requirement in some out-of-tocuh curriculum document in some out-of-tocuh district office), anyone really can learn a language.