The main reason a site might use nofollow relates to scenarios in which that site lacks total control over the links that are added to its pages. In other words, they don't want to show Google a vote of confidence when they don't know whether or not they actually are confident. This is more common than you'd expect; here are a few examples.
https://sharemylesson.com/users/beauty8
![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
