No one wants to play HD games with amazing graphics on 60" screens anymore.
You joke, but the problem is, in Japan this is unironically true for a plethora of reasons. Japan is falling out of love with the set-top hard and it's questionable whether there's really a way to stop the momentum at this point.
An increasingly small number of developers are finding success in the set-top space. You can expect to see more of this sort of thing as we go forward, at least until some kind of tide turns and people begin to wish for more complex experiences than touch-mobile devices can deliver... presuming they ever do.
(Then of course there's the social pressure on adults to not play videogames, and how phones allow them to "conceal" doing this, but that's basically a whole thread to itself... which I think we need to have, although I think there are others who are a bit better qualified than I to write a really proper OP for it.)