There are a lot of banned sites, users, ip and keywords, that autokill the submissions. The problem is that some articles are not so easy to classify. For example "5 tips to optimize your web page conversion" is probably a SEO advertisement spam, but there is a little chance that it has some interesting content and some new unknown information.

The humans check the no-autodead submissions. The amount of very good submissions is very low, so it's not necessary to filter them from the new page.