No follow links to create a link profile look more natural and relevant links from trusted websites. Other advantages such as driving traffic and getting more brand visibility of your website.
It is not necessary that you should not submit a link to nofollow sites because site having nofollow links may also sometimes have large amount of traffic that may help your website to get more visibility.
No follow links are a diversification to backlink building of your website. Though these links are never crawled by search engines, they are much helpful to drive good traffic to your website.
No follow links to create a link profile look more natural and relevant links from trusted websites. Other advantages such as driving traffic and getting more brand visibility of your website.
I totally agree. No follow links create that balance in your backlink profile. You don't want google to suspect you overdoing things or over optimizing by only building with dofollow links. You want a more normal and natural backlink profile.