Fundamental Flaws..
Firstly, Google could easily fix the Android problem. We should just get that out the way.
Second, the XP usage numbers are pure FUD, there's no hard data backing them up, they're based on things like UA analyses rather than doing some sort of census - UA can be manipulated (and extremely commonly they are) so the extent that it's true is wildly exaggerated.
Now - even if these two data points are valid there's a third problem at play. Should the general well-being be put at risk because some people don't fancy chucking their ~14 year old OS away? About a year ago before all this sha1 weakness stuff happened I stated in reg comments that the XP crypto stack is completely broken for reasons otherwise (and I got about a million downvotes despite being, y'know, right), compounded the state of it is putting other users of networks directly at risk by having to keep stuff around we know is broken.
There's only one solution to this: that we kill all this crappy old support. XP users might then start getting the message that their OS shouldn't be connected to the internet.
Biting the hand that feeds IT
