There were probably a thought that older and obsolete content could damage website reputation and rankings. Some were also scared of Panda as if having older content on site may invite Google wrath. Please read more details here : http://www.brainpulse.com/articles/seo-sem/outdated-content-removal-and-ranking.php
I guess the best solution is to create new content or atleast do the updating from to time. Content is pretty much informative. Thanks for sharing it with the community.
. Deleting outdated content can also improve user experience and boost your brand's .You can also use Google Search Console to find pages Google doesn't love as much .