Apple would love to occupy the corporate and public sector desktop market.
There is a difference between would like to occupy/own a market, and be actively working to grab that market. Apple is not fighting for the corporate market. Not saying that they are not go for it at some point, they are not into it now.
Anecdotal evidence and a biased sample - your colleagues are probably in the top 1% of global income, and the kind of people who don't mind spending large amounts of cash on their personal computers.
On the non-biased side: it remains impossible to buy a computer running a normal Linux desktop in a 'normal/mainstream' computer shop. Most gadgets I own, only have software support for using it with Windows or Macs, say, the image processing software that came with my photo and video cameras.
FWIW, someone answered to a post of mine (in this thread) saying "happy I don't care about OS popularity". That misses the point. I can't safely upgrade the firmware in my cameras using Linux. I can't use the (very nice) image processing software provided with my cameras within Linux (crashes under wine). So at the end of the day, at least for me, OS popularity has actual negative consequences. (it is not the end of world, but it makes a difference).
The netbook market fell for various reasons.
Regardless of the reasons. It fell. Linux does not exist (in any significant way) in netbooks anymore. My point is that the netbook gain in market share was an ephemeral thing.