Speaking from my own experience with MB. I thought I was knowledgeable about music and my collection. When I started tagging and adding releases, I found it was like learning a new “foreign” language. Learning and still learning the intricacies and nuances of this program is ongoing. Trying to get everything right is like trying to get your clothes out of the dryer without dropping a sock on the floor.
Fortunately, MB editors are very helpful with grooming noobs. As @outsidecontext said, making it more difficult could lead to fewer editors. Sure it is frustrating to see errors but in most cases it becomes satisfying making corrections and showing the editor what to do in a friendly and helpful manner.