I will agree with you. I'm not familiar with these test banks, but if they are publicly accessible, what's the point in banning them? Here in Greece, all our university teachers encourage us studying any material we can find, even past exam papers, and most provide the papers themselves. We are also allowed to take the exam paper with us when we finish the examination.

If you're a teacher, it's part of your job to write novel test questions. If you can't be bothered to do that, you can't tell people "this is what I'm going to ask in the exam, but don't read it". This isn't even the minimum amount of effort to keep honest students honest.

As another poster said, studying an entire test bank is studying the material.