XP still works for a lot of people - having to re-learn a whole bunch of stuff just because Microsoft needs to pay a dividend isn't a reason for a non-power user to upgrade TBH
Bit like saying I will drive my 30 year old car because I understand it and it still works. Ignoring the fact it is clunky, slow and inefficient when compared to a newer model.
I recently sourced and installed a new PC for a friend whose XP box was getting very old and was past its sell by date. Against my instincts I bought her a machine with W8 on it. It drove me nuts for the first few hours, mainly due to not being able to find anything!
After a few more hours and after upgrading to W8 1 I grudgingly found that I quite liked a lot of it.
However, I received a call a few days later from said friend and she was ecstatic that 'It is so much easier to use, I love it!'. Given that she is an utter numpty when ever I had tried to talk her through something over the telephone when she was using XP to say I was shocked was an understatement. I guess from an uninformed user's point of view MS may have actually made a good OS or more accurately a good user interface.
The differences between W8 and W8.1 are neatly shown
here.