Well, without going into any theoretical biases, it's easy to see why people would think so. If you copypaste the titles of Next Gen articles from Digital Foundry since August, you'll see this.
Xbox One:
Digital Foundry: the complete Xbox One architects interview - The whole story.
Microsoft to unlock more GPU power for Xbox One developers - Kinect and app reservations will be accessible to game-makers.
Digital Foundry vs. the Xbox One architects - "There's a lot of misinformation out there and a lot of people who don't get it. We're actually extremely proud of our design."
Xbox One exclusive Ryse runs at 900p - Full HD off the table for Crytek's showcase. Digital Foundry assesses the news
Xbox One CPU speed increased by 9.375 per cent - 1.6GHz processor bumped up to 1.75GHz in production hardware.
Beyond live TV - what the Xbox One user interface means for gamers - Digital Foundry on the next-gen dash, voice control... and Kinect.
Digital Foundry vs. Respawn: the Titanfall interview - Xbox One, the cloud, the Source Engine - and the 1080p60 question
Xbox One graphics speed increased by 6.62 per cent - GPU receives post-E3 53MHz speed boost.
PS4:
Digital Foundry vs. Resogun - Head-to-head with Housemarque, plus exclusive PlayStation 4 60fps gameplay video.
Mark Cerny: lead architect of... PlayStation Vita? - PS4 design chief also responsible for Sony's handheld.
It's probably safe to say DF is more interested in Xbox One, or Microsoft really wants to talk to them all the time. Or Sony PR could just be slacking off since they're in the publicity lead.