Mouse gestures and keyboard shortcuts both provide a simple way to speed up your workflow. Power users would attest to the fact that switching between keyboard and mouse slows them down. When you know the important keyboard shortcuts for an application, say Photoshop, you won’t go to the toolbox each time to pick a tool, you would simply hit the b key for brush, v for the move tool and so on without moving the mouse away from the work area for a moment.
Likewise it is true for times you are working with the mouse, you want to be able to do the maximum amount of work with your mouse without having to switch back and forth. The very idea of being able to run commands and perform custom actions at the flick of the mouse pointer is inviting. This can be done easily with mouse gestures.