I'd say it's a very safe bet it's from OEMs and the huge number of embedded type system suppliers, who are running hardware that quite simply won't work, or at least not without an uneconomical amount of investment on anything newer.

I know we have some diagnostic kit at work that was still being supplied new on a 4 year lease until early this year, which runs on Win7. If the support for those kind of systems was withdrawn, I'm pretty sure the suppliers would be very quickly looking at alternative options where they had more control over end of life agreements.