Bottom line is XX1 is currently £950, and building a 1x10 setup from scratch with a slightly more compromised gear ratio spread, with very decent components, can be done for say under £200.
At a similar weight? XX1 is super light, to match it you're looking at XX or XTR, and what's the price comparison there.... oh, about the same.
It will filter down, and will be heavier, but XX1 isn't a case of 'this is the cheapest we could go', it's top end kit, with a price to match.
I don't think even the most dedicated MTB fans are going to splash nearly a grand on a drivetrain components of which are the thing that will wear most on a bike. You could buy another bike for that brand new. Cutting edge tech brings cutting edge pricing though.
You miss the point, as above. But yes, most won't, but a number will. If I was building a new race bike for next year it would have XX1 no doubt about it. As it is I'm half tempted to change, got some DT240s I could use, probably get decent money for all my XTR.