Toolbars are always present on the desktop and hidden until you swipe in Metro. Take tabs in IE10, for example; the tabs are always visible on the desktop but you need to swipe from the top to see them in Metro.
Well, the start button is like that. Always present on the desktop in the bottom-left, visible in metro on the bottom-left when you swipe from the left (or swipe-half-in-then-out under default settings).
So I don't think the inconsistency in UI is as glaring as the author states. It's always in the same corner, and whether or not it needs to be swiped to be shown is consistent with the overall UI differences between desktop and metro.