While I agree that there is less and less reason to use XP these days, age alone is a pretty terrible way to judge the merits of an OS.
How old is Linux now?
How old is Linux now?
A more fair comparison would be to ask if he was still using the same distro without doing any updates from the same time the last update to Windows XP was released(which still isn't even fair because it assumes that the updates solve the exact same thing, which they are clearly not).