The real reason
I didn't bother reading all the comments to apologies if it has been said..
Asus wanted to release a small form factor laptop with limited RAM & SSD. Asus wanted XP on it but Microsoft wanted to kill XP and was pushing Vista. Vista was too pricey and bloated.
So Asus threatened to ship them with Linux installed. Messers Ballmer and co laughed and said "go ahead, it'll flop".
Asus sold EVERY SINGLE One. Returns were on a par with any windows offering. It was a runaway success.
Microsoft had to back peddle before Linux got traction with the public. So they extended the life of XP and gave Asus the deal it had wanted originally.
Now a campaign of disinformation was started.
Why would you want a tiny 8mb SSD when for the same price you can have a 130gb ? In other words, the usual Ms tactic of newer, faster, bigger (more expensive)
This of course completely defeated the whole concept of the Netbook being a cheap but robust (no spinning HD) computing device.
Asus were no fools either. They deliberately chose Xandros instead of any major distro so as to not completely alienate MS.
Yup, Microsoft wanted this little upstart dead. Looks like they finally won.