The designers were a very well coordinated integrated group (if there was more than one of them) and they took design imperatives of a restricted palette and fixed pixel sizes to heart.

If you asked the same group to design this now in a world of high dpi high gamut screens they might not get the same constraints out in their design brief.

Google's work on flat responsive was in some ways running against the tide. Skuomorphic was hardly ancient when the Google reaction happened