User blog comment:DaNASCAT/Technical Update: August 15, 2016/@comment-26415383-20160817105703/@comment-24473195-20160817142753

"Given that ii is the very last section on a page, is it something you often expect to be scrolling to?"

As a general rule of usability there are certain user expectations and consistency that user interfaces should try not to break. These are  common so called "golden rules of usability".

To give an analogy, consider going to a bathroom and finding a swimming pool inside. One could argue that as long as there's water to bathe it shouldn't matter. But even if you are just trying to find the toilet seat, the huge pool may obscure its location. That's the point.

In terms of practical use, the category adding tool or whatever you call it, is right there, and is a very user friendly way of adding categories to a page. Except that now when you click the "END" keyboard key you are greeted by something that completely breaks expectations for both editors and casual readers. Readers specifically may be looking for "related pages", categories,  the last part of a page, "see also" sections, or even a navbox to see more content.

They will instead find a huge unfriendly banner like "footer".