For the desktop user, both OSes need rebooting at some point. It's just that the Windows reboot is a much longer, drawn-out process (on either my i3/16 gig RAM or i7/8 gig RAM, no difference in Windows update reboot times) vs Linux, which just shuts down and boots normally.
So it's not just the reboot itself which is annoying: it's the much, much longer time it takes. And for those who say: "well, just go and do what you need to do, and let Windows shut the computer down when it's ready"... sorry, been burnt by that, literally. The system did NOT shut down properly, I had left for work and came back in the evening to find the system hung and hot. This is a fire-danger.
Even if the system were to behave itself during shutdown, when you boot up again after an update, you might as well go make yourself a cuppa: depending on the update, it can take quite a while to finish.
And don't even get me started on the default behaviour - before you change the settings to something more civilised - of Windows to just reboot regardless of what you might be doing and so you end up losing a whole bunch of work. That to me is a far more critical behavioural flaw than if it just - by default - left it to the user's discretion (as Linux does, a far more polite, considerate approach) to reboot when the user has finished what she was doing. It's behaviour like that, and annoyances like having a fully legitimate, purchased copy of Win7 suddenly falling over due to a false-positive WGA process that makes me infinitely grateful for Mint.
Oh, I still use Windows... but it now runs in a VM (whichever flavour I want, XP or Win7, never going with that Win8 nonsense) and since most of the updates are security-focused, I don't bother updating at all. And don't run AV in those VMs... if for some reason the install gets corrupted, restoring from a VirtualBox appliance is trivial: WinXP takes about 1 minute!