Placing it on the start menu was illogical but no one cared because it was easy to find. I can just about see that 'off' might be considered a 'setting', but it's a little bit of a reach.
But, once you know where to find it, it's not that hard.
And as Jim Young pointed out, you can just push the power button. It is by default set to shut down on desktop PCs (at least it is on mine).
Is there any place on the desktop that tells people they're okay to do this? Most users I come across are conditioned not to turn the machine off from the power switch. I know it's fairly safe (I've only ever trashed one WIndows7 machine when I did it), but I certainly don't like doing it.