That "We're a small team and need to focus" comment would sound legit if the game really was XB One exclusive, but developing for the X360+PC+XB One sounds like a a pretty big ask. And given the similarities between PS4 and XB one hardware-wise I would think XB One+PS4 would be easier than XB One and X360.
I don't care that MS bought exclusivity, it's a legit business strategy. But I wish developers would cut the bullshit with trying to give any reason other than that they were paid to keep it in the [in this case] MS family. Just say MS wanted a great exclusive FPS experience for its new console and they brought us on board to deliver it.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix