jQuery is NOT required. He is only using it in the demo to change the selected class on the menu items.
The use of jQuery was to provide the functionality so you can see it in action. If I felt the need I could easily recreate the tabs on a series of pages that do not require javascript at all.
The only reason this might need javascript involved is if the tabs are changing content on the page without loading a new page, such as swapping out divs in a container.
I believe you are confused about design versus function.