[AlexandrB]

Both of you are describing a "waterfall model" of coding, where you conceive of the solution in its entirety before simply writing it down. I don't know if everyone else works this way, but I don't. I prefer to try things in the code and use those attempts to guide and refine my understanding. With the latter approach, being able to quickly and easily modify code is essential because it shortens the testing loop.

Edit: From GP:

> 90% of our time should be spent thinking, and most of that reading.

Reading what though? I assume you mean reading code. If you're reading code, being able to navigate through it quickly is important to maintaining context in your head. If the tool you're using makes navigation hard, it's easy to lose track of what you're doing. Obviously this can be taken to extremes, but spending some time investing in being able to navigate a codebase quickly is not wasted effort.