5. No Backwards Compatibility
This is quite surprising. I know the One and 360 have different core architectures and that makes 360 games incompatible with the One's system, but surely Microsoft could release an emulator. It can be done; I play quite a few Nintendo games from yesteryear on PC. The 360 is a popular console, and for those of us who will get the One, we do not want to have to keep switching between the consoles or have two set up at once; there's only so many (extension) sockets in a house or flat, and only so much space under or around the TV. According to Microsoft, you will still be able to access Live on both consoles.