> earn quality backlinks

Well, at least its honest. For many (most?) of the listed sites, drive-by submitting a link just for the SEO juice would be considered rude.

The directories have to assume everyone is doing it for personal benefit. That's one of their main hooks to gather submissions, and they have to deal with the spam of bad actors.

If your website is a good quality addition to the lists, just submit it. Your exact motivation isn't really relevant if the qualifier holds.