If backlinks to your site have either of these tags they’ll provide zero SEO value. If you use them on your site you will protect yourself from users linking to spammy sites or having an unintentional bad link affecting your SEO.
That being said, a healthy amount of external links with links that are followed is said to be good for SEO too.
Now you have to think widely. Links which is one of the ranking factor from many of other factors like your website speed, contents, UI and UX which are also important. Now nofollow links will be the hint for google for ranking purpose.
The link itself, as a backlink, is useless.
But the traffic, interaction and everything else is not useless. Also the article which will contain the name of the brand is not useless as Google ranks content-aware.
But the whole Google algorithm changes daily and contains over a hundred different factors (only the ones known in public).
Some bigger known updates were Google Penguin and Google Panda for example.
nofollow value is also important to protect your own site from the ranking and content of the linked page.
Nofollow links do have SEO value.
1. Here's an article directly from Google that stats nofollow links are "hints" that provide information about the nature of the link.
2. I'm part of an SEO testing group and we've tested rel attributes multiple times. In every case, nofollow does still provide a boost.
Hope that's helpful to you.