I would approach this question the same way I would the question of why I was taught maths and geography at school. I have never applied 99% of it, but if I wanted to study maths at university I would not be able to without the basics on that. If students aren’t exposed to these things and get a decent handle on them, then they will be hindered if they want to go to further study.
You mention the secondary literature, well without knowing what the terminology is looking things up would be hard and understanding the literature even harder
Although tangential to what you were saying, it is probably worth me answering. The reason I post on the beginners forum is that I assume my questions are going to be beginner level a lot of the time. I tried study through Wales Evangelical School of Theology once but dropped out rapidly due to depression that has hit me regularly through my life. This prevents me from thinking clearly often, and is so at the moment, so I would prefer to assume that I am missing something obvious. I recently did two out of four Greek modules with BibleMesh; again depression prevented me from continuing. Without knowing whether I actually have a grasp of the subject matter, it seems more reasonable to assume beginner level.
I should be a lot better at reading Greek than I am now if I focussed on reading the language and not about the language, so I definitely know what you are saying here, and agree. It comes down to what you are learning the language for though.