Apple have something like a 10% market share. I think what you see in coffee shops and on expensive commuter trains is not at all representative; if you go into a Starbucks in a trendy part of east London, you'd be forgiven for thinking that Apple had a 95% market share, but I'm pretty sure if you go to, say, eastern Europe you'll see very, very few Macs.

I have noticed that as well. Mac users seem to feel the need to use them in public for some reason.

This could be explained by Macs working better on random networks and having better battery life than other laptops.

Anecdata: I know of several Windows laptops, but only one Mac laptop, which are now effectively desktops.

Did those laptops start out as expensive as a Mac, or were they low end machines?

Apple's PC market share is much higher in the USA than it is worldwide, and it's very low in Asia, apart from Japan.

Also, Apple's market share is much higher now than it was when the masses adopted PCs. That happened under Windows 95 (which nearly drove Apple out of business) and XP.

When Windows brought computing to the masses, Apple's global market share was closer to 2%.