If they do ever allow cross platform gaming where people with PC, XBox and PS4 can all play together at the same time, I hope they will make separate game modes for controller players and mouse/keyboard players. If that's even possible.
The controllers are a big money maker which offsets costs for them, which is why they've clung to it for so long.
but as far as game modes, you don't want to mix because of PC- hax..
I don't think that's why they have clung to them so long. Controllers are the essence of console and what makes them living room/multiplayer friendly. Sure, there are lapboards that allow for keyboard/mouse PC gaming in the living room, they work really well and I own and use one. But, they are big, awkward to store (leaning against a wall or under a couch), 15 feet of cord to worry about and very expensive vs controllers. Who wants this mess in their living room all the time?

I'm all about PC gaming but I would be really sad not only for myself but the millions of other people who have grown to love controllers over the past 30 years or so. Controllers just feel more natural for gaming. I would be pleased as punch if full controller support was offered for all PC games. But some are just not designed with controllers in mind and would not work. Diablo 3 being the exception. Controllers work surprisingly well for Diablo 3 on console.