True, true. But there's miles and miles of difference between "You should reboot at your earliest convenience, but it's ultimately optional" and "Microsoft's computer is rebooting NOW -- better hope you weren't planning on doing anything important in the next 30 minutes."
(Oh yeah, and about that '30 minutes' part -- On Linux, you reboot to apply updates that are already installed. The update reboot doesn't take any longer than any normal reboot. On Windows, for some dumbass reason, the update has to be installed during the reboot, which can make the mandatory reboot take much, much longer than a normal boot.)