There's another dimension to "fairness," that is embedded in most national legal systems as well as implicitly included in the ODP guidelines. And that's the temporal aspect.
The first guy to publish a new idea has special ("patent") rights. That may not be fair to the second guy to publish, who really had the idea first but was in the hospital at the time: but it was considered a good deal for society -- it encouraged people to publish good ideas, and after 14 years or so, anybody could be using them.
The first website to post e-texts of the complete works of Sir Walter Scott has certainly created unique content. The second website....probably hasn't. And the ODP lists "unique content."
Now, there are ways in which the second edition may be better than the first, and in fact the ODP often lists several versions of classic works: some in ASCII form, some in HTML, some in annotated hypertext, some on standard archive servers, some at authoritative but shortlived academic sites, some integrated into personal fan pages, etc. (And I've published some XML versions of texts previously available only in ASCII or primitive HTML.) But after we've a half-dozen copies of a text, then we really have to ask: is this ADDITIONAL copy really worth it?
The sites you mention have been around longer than yours -- so to be "fair," in the socially accepted theory of creativity, they SHOULD be treated BETTER. (How much better? editor discretion.) And, to the extent that those sites have content similar to yours, they reduce any conceivable value that yours might add to the directory. And to be fair to the USER, the presence of similar sites raises the bar for your site's judgment.
Life is like that. You can't open a new gas station across the road from an established station, and expect to get business charging the same price. You've got to add value somewhere.
So when you say, "my site is exactly like 20 sites that are already listed, so you must list it," You're not even barking up the wrong tree, you're digging a hole for yourself on the wrong side of the forest. What you _must_ be able to say is, "my site is totally DIFFERENT from all 20 related sites that are already listed" -- and yes, we know that that is a harder thing to say than "my site is different from all 3 sites already listed."