DesignHammer articles aren't about Drupal

Those articles are about the organization (for example, the meaning of the organization name, its 20th anniversary, its logo), not about Drupal. I have removed the articles from the feed, and suspended the feed.

Thank you for the following up!
I changed the update interval to Never and removed Planet Drupal from the destination of the feed items. In this way, no new items will appear on Planet Drupal.

I usually link the issue created for adding the feed, but in this case I cannot find any, on this issue queue. It could be it has been created on a different issue queue, since we did not use this issue queue, years ago.

I found it and moved in this issue queue: It was on the site moderators queue.
The user who asked to add the feed to Planet Drupal does not work for DesignHammer anymore.

I also change the title from DesignHammer to DesignHammer (See https://www.drupal.org/project/content/issues/3225954.) Everybody who edits that feed should see the link to this issue.