Linked- Who Just Paid Microsoft Millions of Dollars for Continued Windows XP Support?

Short answer- the Navy.  Over 100,000 units still in use.

I wish this was the only scary example, but it’s not.  Countless ATMs, Registers, and other financial tools are built on XP as well and continue to be long after official support is done and gone.

This is the classic dilemma that defined much of Microsoft in the last decade.  They'd grown so large on the success of the enterprise that it became a hinderance to change.  It's why Windows 8 adoption continues to lag. 

I hope the newly crowned "Windows 10" turns it around.  I'm a big fan of Microsoft theses days and the new directions they're taking.  But as long as they keep depending on the enterprise for their bread and butter, they're going to have to fight the "what works is good enough" mentality that users have.  Guess we shall see...