Well, if I was for some reason still using Windows XP - there are legitimate reasons - and using it to access the Internet (some part of me really does not like that idea), at least I would want some browser that was not an ancient version of Internet Explorer.
Now that I think of it - cough - I do have XP installed on two machines, but I installed Ubuntu alongside when I got them, and I cannot remember the last time either machine actually booted XP.
Another reason I prefer XP is just bc it worked so damn well. ITs not full of this shiny Aero junk that Ms pushes on us now with these ads on the side asking us to play candy Crush
Now that I think of it - cough - I do have XP installed on two machines, but I installed Ubuntu alongside when I got them, and I cannot remember the last time either machine actually booted XP.