Not trying to join the constant moaning, and I will give it a shot, but as a pro FCPX editor, the very idea of using the tiny touch bar image to scroll within my timeline based on the image is the sort of demo that can only be created by somebody who doesn't use the product on a regular basis.
The thing is, the trackpad on macbook pros is already so good at this, as is COMMAND =/- for zooming in and out. These are tactile functions, and my eyes never need to leave the screen.
If I can map out a bunch of custom functions, I can see a use for it, but the timeline is worst example I can think of for FCPX.