Join Date: Apr 2002
Location: Montréal (Québec)
There are historical reasons for that. Back in the 8-speed days, Dura-Ace derailleurs pulled a different amount of cable than anything else. Shimano had Dura-Ace 7-speed, then 8-speed bar-end and downtube shifters for Dura-Ace rear derailleurs, and Ultegra 7-speed and 8-speed shifters for everything else in the Shimano world.
Starting with the nine-speed era, all derailleurs are now created equal, and there is no need for two sets of downtube and bar-end shifters. So they just kept the Dura Ace ones... and kept the sticker.