Why is there a small delay where you have to drag up/down a small amount before the drag-zoom function begins to work on the ruler?
An immediate grab would be far better and more accurate. The small delay catches you off guard.
Any delay in executing mouse functions is a big no no for workflow design.
Drag Delay Allows you to set up a delay in ms that is used when you move events. This is useful to avoid accidentally moving events when you click on them in the Project window.