Re: Lack of integrated email/contacts/calendar?
@t.est they already had the PCs, they just needed to reprovision them. That is a lot cheaper than throwing away 15,000 perfectly good PCs and buing 15,000 new Macs... Replacement cycles would also be longer on Linux / Windows, given Cupertino's glee in stopping support on older hardware.
Also, don't foget at the time of the transition, that would have been transitioning to PowerPC, maybe there was something technical - such as the VMs for keeping virtual Windows instances around for special programs that didn't have a Mac equivalent were so abysmal back then... Now they could use Parallels or VMWare or even dual boot with Bootcamp, back then it was Microsoft's VirtualPC, which was a dog.