Right, most are for inbound links and because people see some of them charging money for a link so they want to get in on that. I think those built for those purposes will eventually get the axe and the niche specific ones will survive. Yours is a good plan for linking people to SEO related resources but it would be better if it was a feature offered by some kind of SEO website.
Just a cruel fact ... Would Google create a blog search if there weren't at least 8 trilion blogs online ? At least , from people that i know, all great people, great ethics, generally speaking... make tens of blogs .. with crap content (SE content, not user content) just to host links.
Professional human edited directories with well developed databases have been around much longer then search engines and will be around for many, many more years. The newer hobby, take your money and run directories are just a fad and will either get axed by Google or simply cease operation.
I too have a directory, simply because i enjoy classifying websites. Now you can say you've heard it twice
Niche directories are always needed, as long as they are run by people who love the niche and can dig deeper and give value. General directories are a dime a dozen, but I will still submit to as many as I can until it proves to be not worth the time to do so