2/ Obviously, many people believe that Windows can't count as Linux because... reasons.
I'm sure you all have your reasons.
But let's just pretend you're right.
Even without Windows, Linux commands over 5% of the desktop OS market.
That's probably a conservative estimate because there's a further 5% of computers for which we can't account for -- and a good many probably running Linux.
"But that doesn't count because so much Linux is just Chromebooks!"
Thus goal posts get moved...