Actually, all cameras that can't place phone calls have long since become niche products.
Good point.
If you look at ALL picture taking that's true.
If you look at the subset of "dedicated cameras" then you can again see, within that set, there are "mainstream" options and "niche" options--again that's within that context.
And that was the context I was thinking of. But it's good to be reminded of the Bigger Picture every once in a while.
And yes, I forgot the wildlife shooters; I was mentally bucketing them with "action" but many of their concerns are quite distinct.
As for what Canon wants, I think you're likely at least partially right. I suspect they want to make a mirrorless that will be satisfactory to everyone, but they won't be bummed out about it if it never happens; they'll just crank out Ms, Rs, and EFs. They're big enough to survive doing that; other smaller companies will have to choose one or the other.