If the XBOX or PS4 (as well as game developers) would just take the mouse and keyboard seriously
Sony takes mice and keyboard seriously with their Playstations. PS2's, PS3's and PS4's have USB ports for a reason. However Sony leaves it up to the developers to decide if they want to support keyboard/mouse and in what way. Requiring mouse/keyboard game control is probably not in their TRC requirements.
PS2: If a game has text chat or text entry, it almost always supports keyboards. That includes the settings disc for the Network adapter, and RPG Maker Keyboards/mice for game control is rarer, a few FPS's do like Half Life, FFXI, EQOA,
PS3: If a game or app uses the PS3 text entry widget, it automatically supports USB keyboard. Game chat, naming enchanted items in skyrim, signs in Minecraft, whatever. Keyboard for game control is rarer, again a few FPS like Dust514...but strangely, not the Orange Box. You can use keyboard/mouse to control the XMB.
PS4: like the PS3 there's pretty much automatic support for keyboards for text entry. There's at least one game that can use mouse/keyboard for game control in addition to chat and that's War Thunder. War Thunder also supports HOTAS, and uses the the PS4 Camera to use head tracking for view control.