Why Some Still Don't Change To NoFollow?

Hello there,

While I really love a lot this plugin of yours in the first go BUT I got one more question here. although majority of links had turned to as nofollow BUT still some yet to update to nofollow. Why is it so?

I am using WP 3.8.1 plus WP SuperCache as a plugin in my website.

Please reply.

Thanks
Karan

https://www.ads-software.com/plugins/auto-nofollow-links/