Hmm... this is a load of BS. Sure, many people opt for XP on their Minis (I did so for two reasons: 1) Financial, and 2) I needed another XP install CD), but that's no reason to completely wipe their stock! It doesn't compute.
I myself like Linux, because Microsoft needs another competitor. OS X is pretty big, but that in itself is not big enough. Either Apple needs to open up/people need to make Hackintoshes, or someone else needs to make an OS that can dethrone Windows as a big competitor (and maybe raise Apple as well).