It keeps us sharp and on our toes. We will always benefit from the widest possible range of ideas and techniques. Diversity brings the universe to our door. But then, just as important, is the process of deciding what to take in, what to modify, what keep out. The decision point and cut off should be as close to the everyday moral life of the community as possible.
Diversity offers humankind a smorgasbord of options.
We can't, and shouldn't, take them all. I also share Rosemary's preference to keep submission informal and brief. At a simple level, the case for diversity seems so obvious - we learn and grow by being exposed to new and varied experiences and perspectives, so that we can select from them to determine our own opinions, and not merely inherit them. Acceptance of diversity expands the range of individual choices that society tolerates or supports, allows us to get beyond categories and stereotypes, and permits or encourages individualism and personal fulfillment. From my own experience, I believe that diverse groups make better long-term decisions but take longer to reach them.