It is not a more illogical place than the start menu to be sure. The only problem with it is that it's hard to find, because unlike its previous spot it's not in your face the whole time.
One thing I don't know is why there's no shut down option under your username on the start screen. I mean, there's lock and sign out there, having shut down there would both make sense and be easier to find.
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).