Makes sense though, business wise.
Keep the cost of the machine low, 'cause the custom made controller (Kinect 2 for MS, WiiU controller ripoff for Sony?) is gonna add to the cost. People in this economy are not willing to throw out 600 bucks for a new system.
If Sony wants to charge no more than 300-350 bucks, they have to resort to weaker hardware. Not that anybody, except crybabies from Epic Games, really cares nowadays.