How is this really surprising though?
If you release a system with the memory bandwidth of lower then a 6770, and the overall capability with CU's and such of maybe a 7770. How do you expect 1080p x 60fps??? If I bought BF4 on my PC with my GPU, which is a 6770, I would expect to have to turn down a TON of EVERYTHING to get 60fps. I would have to settle for 30fps with dips going even lower and still have to tune down a lot of things.
The X1 is ... not ... powerful. Compared to the 360, yes it is powerful ... it is an upgrade. But the X1 was ORIGINALLY DESIGNED as a multimedia box. Not as a pure gaming machine. The bandwidth of this system will be the death of the system, from the get-go.