"But don't Macs have a larger share of the 'technically-minded-user' / 'geek' (whatever) market than Wintel?"
Not in my experience... do you have the data to back that statement up?
I'm pretty sure that here on Hacker News there's a pretty even split between Linux and OSX. There's even a pg essay on this phenomenon written a few years back that I'd link for you if I weren't on an iPod touch.
Edit: this should be it:
http://www.paulgraham.com/mac.html