And that's not good. But that's badly done assessment, I'd argue. Good assessment is a boon for teachers. It helps us understand our work, and it helps us plan. It's organized reflection.
Portfolios are a wonderful mechanism for inviting students into assessment cycles.
Writer's letters, or other reflective pieces in which students write about their work to a supportive audience, are another. Assessment can help make students more aware of their personal goals, and how those goals intersect with institutional goals. It provides students with a way to make their own contributions to grading cycles. There are several principles to keep in mind. So the first rule of thumb is to keep it simple, and know what you want to find out before you start.