Search engine robots are cleverer than before; this makes SEO different and more difficult than ever. They can easily spot directory submission sites that are merely for the purpose of link posting, not even arranged by categories. Most of them are free-for-all sites that offers free link posting. They are certainly link farms that would only make your site spammed. Better be also clever enough to spot them so that you can avoid them.
Some of the search engine optimizers are just copy-pasting the paragraph from a website or Meta description of the site to all directories. This is one of the identified spamming methods by the search engine robots. The great way of doing directory submission is to spin or vary your wordings to make every post unique.
The more links on the page, the less page rank is distributed. Better search for web directories with less links every page.
It used to be a thing in the past that directory submission is the easiest and fastest way of ranking in Google. Since the discovery of spamming through web directories, everything has changed. This calls for opening the eyes of the search engine optimizers to change the web optimizing technique into more ethical.