Mac OS X for its era was astounding. Think about it. The ease of the Macintosh (journalist, media people) that's it, a good looking OS and the security and Unix tools preinstalled which would be helping ex-Solaris/Sparc departments. As it was shipped with XQuartz, a Terminal by default and tons of Unix utilities, even Motif worked, so porting expensive Unix stuff between Solaris, Linux and OSX was a breeze.

Windows... well... w2k was for companies or the enterprise, people followed Windows 98SE as if it was a cult and ME was a polished turd. W98SE was crap on security, FAT32's performance for an installed OS was a nightmare, having to defrag a lot and performance degraded a lot over time. You had to format and reinstall once a month. Oh, you need to reinstall the chipset, soundcard, and video drivers? Some BSOD on the process will be guaranteed.

Linux and KDE by 2004 was nice, but broadband wasn't everywhere and setting it up was not as easy if all you got from a retailer was a Slackware/Debian DVD with an installing book. For everything else you had to be ready to learn a lot. And X.org wasn't as ready as today.

OFC my KDE3 setup from 2004 with bells and whistles like the Nvidia Geforce 2 drivers was nearly on par on OSX' features, (even with Cinelerra and JackD) but OSX set it up everything for you by default since 2001-2002.

Even Microsoft Office under OSX looked beatiful.

And today, ironically, I'm almost the opposite, by using CWM, void, OpenBSD, groff+ms, sc-im, Gnuplot and so on.

But to each its own. OSX by being a Unix helped Linux/BSD's a lot too, even if it took a huge chunk of market. CUPS polishing, (CUPS ofc worked pefectly in 2003 without Apple's support, but I think Apple gave them more support on weird printers), Bonjour, HTML->Webkit...