But remember that Chromebooks are a US only story. There are very few of them outside the USA. One good year in the USA doesn't gain many percentage points in a worldwide stat.
Once in a while, in a blue moon, I see one single device at Saturn megastores in Germany. Usually it stays at the store with increasing "product of the week" discounts until someone finally takes it away.
In Portugal, Italy and Greece I am yet to bump into a store selling them.
A lot of enterprises are beyond proxies and many places don't allow you to access internet outside a few select sites
So they switched to Linux because well, not because it's Linux. Funny :-) You probably meant : they switched to Linux for none of the reasons HN's readers like Linux (open, free, people-like-us, etc)
Think if I hadn't started with KDE at that time I would be much more fond of OS X.