Mashable is the authoritative source on all things Social Media. So it stands to reason that articles from the authoritative source on all things Social Media will often start trending on one of the top Social Media platforms, because people are sharing content and learning more about Social Media.
It does get quite annoying. But it will continue. Mashable is a great site, and articles will continue to trend. So rather than getting annoyed, let's make the most of it.