Well, maybe so. It might depend upon your perspective about a common question bank versus a question bank for each course.
Let's say, that someone finds an error in one question. If the question bank is common, fixing the error would fix it for every course using that question. If you had separate question banks, the question would need to be corrected in every course.
I once used Blackboard, which seemed to duplicate the question bank per course. I discovered that if I had two of the same course in one semester, that if I found an error in one question, I had to make sure that I fixed it in both courses. This bothered me. When I switched to Moodle, I loved that I now had a centralized question bank, and I wouldn't want to do it any other way.
But I can see that some might want decentralized question banks.