I must admit that XP is part of the equation in this. My sis is one of the people for whom I'm the "tech support". She knows that I'm getting rather tired of dealing with the various XP problems and oddities people seem to frequently have. Her still running Win95 (on a Pentium 120!) has actually saved her a bit of grief; but there's just so much that OS can't do (or at least can't do
well). Put a fork in that computer; it's done!
We've got an XP box at home that hasn't been too much trouble; but having direct control over it makes it easy to enforce good practice - plus my wife is pretty good about not doing the silly things some users seem hell-bent to do. However it's not like I can set up a group policy and lock down my sister's computer (or my mom's, or my friends', or ...). Okay, technically I
could, but politically...
Plus having had the past 1.5 years to compare OS X and XP side by side, using them both with the same types of hardware and software - it's made it easy to sell OS X on its own merits (as opposed to going the negative route: "Use OS X because of XP's shortcomings").