Reddit very successfully moved away from being the techy nerd basement dweller site to becoming a trendy young "normie" people site. Dumb everything down to shoot for the lowest common denominator, maximizing the size of your target demographic.
So hiring someone who probably loved instagram, facebook, pinterest, tumblr, but never used reddit (but had likely been to the site perhaps a few times before) is exactly who they wanted to redesign the site.
IIRC something like 95% of users are using the official app and/or the new website. And reddit has exploded in popularity in recent years.