I see this all the time in manufacturing. A lot of places still have machines running Vista and even XP. I JUST upgraded a Win7 machine not even an hour ago.

Giant pieces of equipment will come with consoles or computers that have these old versions of Windows on it. Said piece of equipment costs $100,000. Said piece of equipment WILL NOT work with any other console or computer. These businesses are not going to spend thousands and thousands just to upgrade Windows when the equipment still runs 100% completely fine.

You can still find replacements for these systems on EBAY and stuff too. When one dies it's faaaar cheaper to buy a 15-year old console on EBAY for $6,000 than it is to spend $100,000 on an entirely new machine.

It really is common sense from the owner's end when you think about it.