I may have this wrong, ("for all PRACTICAL purposes", was said) but i don't think a group or single editor should have the power to decide when a topic has been covered enough. No catagory should ever be "finished". New information is always coming to lite on the web on any topic you could think of evaluating as "edited well enough".
That might be true if you had editing permissions in one or two small categories (which is what you have in your mind, I think), but, many of us have higher/wider editing permissions and we may roam through thousands of categories and subcategories.
For instance, I have US level permissions, which means I can edit in every locality in any of the 50 states, and every subcategory located in them. That means thousands and thousands.
I may be passing through a state and notice an area that really needs some serious work. Perhaps a former editor got a little sloppy with the proper Titles and descriptions, and it bugged me so much that I decided to stop and fix them, or there were a lot of sites that needed to be sorted to the proper sub catagories, or that I needed to create those sub categories. (editors do lots of different jobs besides reviewing site suggestions).
So, I'll stop there long enough to do those specific things because I feel they can't wait and I'll say good enough for now, but, I won't neccessarily stay there and go over the category with a fine tooth comb, I'll move onto the other jobs I set out to do.
I think that might possibly be what editor hutcheson was refering to in that quote, and he is a meta editor with much higher/wider editing permissions and duties to fulfill than I have,
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If you're editing in one or two smaller categories, then you have the time to really spiff them up, find new sites on your own, and if you feel like it, go through all of the site suggestions that may have been submitted to those categories.
Added: Gotta learn to use all ten fingers, I'm slow.