I can understand what you're saying, and I agree, but I think you miss the idea of abandoning the mouse. You're not doing it with intent to lose the marginal be

I can understand what you're saying, and I agree, but I think you miss the idea of abandoning the mouse. You're not doing it with intent to lose the marginal benefit of the mouse, rather, you need to give it up in order to become more efficient and familiar with the keybindings. Thus, once you are no longer a beginner (the guide's target audience) you may graduate to keyboard+mouse. I don't use emacs or vi(m) or anything truly in line with them (textmate is my closest) but I have no doubt that someone who uses only the keyboard for three months and then reintroduces the mouse will show a greater capability with the tools than the same person spending the same time using both keyboard and mouse.