At the time there was also a major push to bring desktop computing and the web to the general population, remember this was a time when cutting costs enough to market a $1000 PC ($2000 adjusted for inflation) was considered a major achievement, the very bottom of the market. I get the sense that Apple was trying to distance its design as much as possible from square-cornered beige boxes as possible to signal that the products were for normal people.
This; and that WIndows 2k was as stable as OSX (compared to w9x and the ME disaster) but... it looked functional but boring , as a brutalist building in any European neighbourhood. Mac OS X blended both the incredible FX you would get from an SGI machine... with all the A/V and printing/design Mac tools, most common PC software (Office, Photoshop)... AND being able to run damn LaTeX, X11, Unix tools and the like. Of course even Windows XP wasn't a match against a G4 with OSX Tiger. They tried with VIsta (after Compiz and KDE3 tried to get tons of OSX' inspiration under GNU and BSD) and it was a disaster.