Having an iBook or a PowerBook with Mac OS X was a big deal at a time when driver support for Linux was less commonplace than it is today. Even today there are driver issues with Linux on some laptops.

Part of the reason I bought a Core Duo MacBook the summer after my freshman year of college was because Apple was the only vendor I knew where I could purchase a fully-supported Unix laptop. It could also run Microsoft Office without having to dual-boot with Windows, though ironically I ended up just using NeoOffice (a Mac fork of OpenOffice), the Apple iWork suite, and LaTeX during my college years.