Is Linus's vision really this narrow?
It's not the x86 architecture (or even the AMD64 architecture that replaced Intel's failed attempt at "industry standard 64bit") that means there's a lot of x86 about, it's the Wintel monopoly and the resulting vendor-defined architectural specs, going all the way back to (e.g.) the Lotus Intel Microsoft specification for "extended memory" (or was it "expanded memory") in the world above 640kB. Which led in due course to things like the PC98 spec and so on.
When there's no PC98 spec (or equivalent) to hold things together, x86 hardly gets a look in.
Outside the world of the Wintel-centric IT department and its consumer equivalent (and outside the world of Apple too) there's a lot of ARM and not a lot of x86, But the ARMs are often invisible to Joe Public, and apparently invisible to Linus too, if the reporting here is to be believed.
Imagine a world without ARM. It'd be a bit different. Nokia-style mobile phones, except with a battery life of two hours. Portable 2.5" disk drives with a capacity of hundreds of MB not hundreds of GB because they haven't the space or power for the x86 version of the ARM-centric embedded processing disk drives have all been using for many years - how many of them are using x86?
And so on.