who has a Mac? everyone!

Your experience is so vastly different from mine that I can only assume it is either regional, or because you mostly work with/know people in the technology sector, where I would expect Macs to have a higher market penetration. My (unfounded) perception is that Mac users are more likely to be technology enthusiasts who have made a deliberate choice.

Or possibly, given the cost, they're mostly owned by people who are rather outside my social class.

It would be interesting to see how Apple rate their market share across different countries and demographics, but I'd be surprised if they published such information - it would similarly be lovely if Google's zeitgeist still included data on OS market share. I guess the data-mining opportunities are to great for them to want to share that.

(One final point which may or may not be useful depending on what you think his opinions are worth: even Steve Ballmer thinks that Linux is more popular and a bigger threat to Microsoft)