Also, when it comes to programming, the biggest bottleneck for most people isn't typing -- it's thinking.
P.S., there do exist mouse-heavy programming environments: http://en.wikipedia.org/wiki/Visual_programming_language
I'm not a neurologist, but I wonder how differently the brain's spatial centers and language centers interact with the part(s) that perceive the passage of time.
The same thing for those mouse-centric applications. Linux window managers have a "shortcut" of holding a modifier combination and dragging anywhere within a window to move it, or dragging the nearest corner to resize it. This makes arranging floating windows fast and fun compared to Apple's more intuitive requirement of having to drag the titlebar, or that tiny little handle at the bottom right of the window.
Some of the mouse-centric visual programming environments you mention, particularly the ones that have many years of use behind them, also contain shortcuts. Autodesk's Flame compositing environment for instance, traditionally driven via a pen and tablet, has a whole bunch of shortcuts to drive the interface without touching the keyboard. You can connect dataflow nodes by "kissing" for instance - dragging them close to each other, allowing you to connect many nodes with a single movement.
For many people, it's the mastery of these shortcuts - keyboard, mouse, pen or touch - that gives them a sense of pleasure and power when they use that piece of software.
That's so true for me. I'm not pumping out code nonstop where the efficiency of keyboard vs mouse comes into play. Being more efficient with moving around a source file only matters if I actually knew what to do once I get to a particular spot of code and many times I don't. I struggle more often with the high-level design of a program than the details. And when the design is sorted out then everything else falls in place. That's when more efficient navigation may be more important to me.