IMHO Vim's strength come from the ability to operate on any logical chunks of text in a unified manner. Being able to jump around text with the keyboard is hardly a big deal compare to that. For example, to delete the entire body of a function in C, you can type "da{", where "d" means delete and "a{" points to text surrounded by braces. To delete a single sentence, I can do "das", etc etc. Of course, you could do the same using the mouse by selecting text manually, but it's way more tedious than Vim commands.