"Become Editor" link not avialable in category

While attempting to volunteer my services as an Editor to a specific small category I have discovered the "Become Editor" link is not available for this category. Can someone, Editor or other, explain why this link may not be available on certain categories. I can see it being reasonable on a huge category, but that was not the case here. There were less than 100 total listings.

Also, I did search the forum before asking this question. I can't find anything indicating this link to not be available on particular categories. Perhaps I used the wrong key words, but I did give it a go before asking.

Which category is it?

Quick note - I dumped the listing to Excel to get an exact count and I was wrong ... there are more than 100 listings, not less as I had stated in my initial post. Don't know if this makes any difference as to why the link doesn't appear, but I do want to supply correct information in regards to anyone researching the issue.

The category isn't suitable for beginners; that's why the link isn't there . We recommend a category of fewer than 100 listings to start with. This one has 177.

Please choose a different one - perhaps one of its @linked subcategories.