So where are the Windows supercomputers?
that is a stupid question and shows your lack of understanding of the topic. Windows is not MADE for supercomputers and never was or will be.
But the people who used to laugh at it when it first came out are the same people who laugh at it now, $trillions in revenue later.
Unix/Linux STILL does not have a user friendly interface grandma can just turn on and use to email recipes to her bridge club, and it probably never will. But its perfect for supercomputing.