MS problem is less about diversity and more that they don't really have any hit exclusive IP. They've rested on their laurels since Gears Of War, which attracts the same audience as Halo.
Even Nintendo has made new things like Wii Sports, Splatoon, Animal Crossing, etc. since Halo, but MS really has not.
Sony has created The Last of Us, Uncharted, LittleBigPlanet, which have had commercial success to some degree at least (Uncharted and LoU primarily).
I guess they bought Minecraft, but that was already successful on the XBox beforehand, so they're not exactly bringing in a new audience with that IP.
But MS has been riding Halo for far too long. They need something newer than Halo, you actually don't need crazy diversity with your 1st/2nd party titles (provided you have 3rd party support which MS does), but you can't just sit on one IP for 15 years and simply try to ride that forever. Forza and Fable are freaking tired too and where never that big in the first place.
MS needs a hit original IP that isn't similar to Halo. That's their issue.
