What is the advantage in submitting in a directory that has article directory in it. We already get one link from directory submission, why do i have to submit an article to get another link back?
You get a link back to your website. But many sites that host this type of service don't work anymore because they got penalized by Google.
Usually an in-article text link is more relevant than a simple listing link, so that's why usually people go for both. Sometimes, their article directory section may have a better pagerank or link distribution structure than the simple web directory. Sometimes its like you say, just not worth it, especially since article and directories has lost some of their power recently.
But, these kind of directories do not allow links in article. Most of them just allow a URL to be posted.