There's more than a bit of leftist elitism at work. E.g. I once made the mistake of submitting something from breitbart.com. It never appeared in 'new'.

When I'm logged in, it shows me that I've submitted 5 items. Examining my submissions anonymously only shows 4 items. Perhaps there are 5 if someone has 'showdead' on?

Putin's external propaganda site, rt.com, is OK, heaven forbid that Breitbart be afforded that same privilege.