I think he did that so that he could have a lower mount for aerobars. He came up with another solution to the problem, found elsewhere on his site, where he had a special K-shaped stem made...the lower leg of the K extended below the roadbars and was used to mount the aerobars. But, if you imagine this, you would have to place your arms under the roadbars to rest in the aero position...which, I imagine would be difficult to get out of if there were an emergency. So, I think this is his carrying forward and improving that idea.

His site is valuable, to me, because it inspires innovativeness and outside-the-market thinking...and I have to admit I like that as much as riding. elaboration on his K-stem idea