Thanks for bringing this up. I suspect a few of our tags have similar issues, including professors. But let's start with this one for now. My two cents....
So first, we already have an undergraduate tag. This is for questions related to providing teaching, advising, or research mentorship to undergraduate students, and excludes questions that could also be relevant for post-graduate students.
We do not have a corresponding graduate-student tag. However, we do have a supervision tag, which in practice covers most of the academic services that faculty provide to grad students.
So, I am not sure why we need a students tag at all. Most questions "about students" (e.g., their characteristics and preferences) should use the undergraduate, supervision, or teaching tags. Questions from students should use the appropriate tag (e.g., advisor or academic-integrity or grades or whatever the issue is). If there are on-topic questions from students about issues not covered by our existing tags, we should create those tags rather than falling back to a generic "students" tag.
Sadly, the only way to implement this would be to remove the tag from all 449 questions (which will bump each of the old questions back to the front page). We could do a couple per day for the next few months, but this is a major decision; we should make sure we want to do this before we commit to it.