The "problem" with the mouse is Fitt's Law. It is easy to use the mouse to hit large targets but, as the size of the target decreases, the duration and complexi

The "problem" with the mouse is Fitt's Law. It is easy to use the mouse to hit large targets but, as the size of the target decreases, the duration and complexity of the task augments. Since we, as programmers, deal with very small targets, using the mouse is not the most efficient way to go. Some editors allow us to move very quickly to the next opening bracket on the line (Vim's f{ for example) while most editors can't help beyond a certain point (usually the OS's word-by-word jumps). If the only means you have to reach that opening bracket is a dozen presses on the right arrow or the mouse… well, the mouse may have its chances. When you can do f{ the mouse is simply useless. Also, the motion of the mouse is non-linear: you have typically a fast startup followed by a progressive slowdown until you reach your target. That slowdown happens because the fast startup was done in the general direction of the target and must be adjusted a few times to hit the target accurately. Another thing to factor is how often you use the mouse in your workflow. When I do mouse-y tasks (Photoshop, browsing…), the mouse is my primary way too interact with my programs. My left hand is available for hitting modifiers or changing tools while my right hand is almost always on the mouse. In that context, I never loose the pointer and the mouse. Changing from task A to task B with the mouse is easy and costless. When I do keyboard-y tasks, the keyboard is my primary means of interaction. I can spend a lot of time typing stuff, moving around… without touching the mouse. When I want to use the mouse I usually don't really know exactly where it is — that's a first problem — then, when I grab it, I don't know where the cursor is — second problem — which makes the initial targeting slow and error prone. Once the first steps are dealt with, the limitations in Fitt's law apply. That's why the mouse is frowned upon among people who use primarily the keyboard.