What's the purpose of an academic exam? Generally, exams are meant to evaluate what knowledge and skills a student has gained, and the way an exam is designed determines what skills are tested.
A general example of this is multiple choice vs free response. Multiple choice questions test recognition-- selecting one correct answer from a finite, visible pool of answers. Free response questions, on the other hand, test recollection, determining if a student can identify a correct answer without being prompted.
What would happen if students were allowed to look at their notes during an exam? Understanding and memory would probably be less vital, and note-taking ability would be the major skill tested.
Next, what would happen if the professor made available all possible questions on the exam and their correct answers for students to study before taking a take-home exam? Two things are tested in this case: short-term memory, as looking over the question bank right before taking the exam is a no-brainer, and moral soundness, for cheating on such an exam would be extremely easy to do and get away with.
With the question bank so readily available, it's hard to imagine that anyone in the class would get less than a 95% on this exam, so it's safe to say that knowledge and skills aren't really being evaluated. This isn't something I should be complaining about, but if exams are my roller coasters, this one was a merry-go-round.