Maybe the thought of buying one brings up mental images of going broke?

Decent hardware that Linux is happy with is definitely much cheaper than a decent MacBook.

They can't afford more mouse buttons?

That'll be the "next big thing" they'll gushing about on stage: an incredible new mouse with TWO (2!) buttons! Of course, it'll be a $600 upgrade...

Linux seems to be the only OS that makes good use of the middle mouse button, unfortunately many mice are not designed for that kind of wear on the button, so this is always the first to break :(