But the developer wasn't going to take this brain-dead approach; he was going to do something that would actually help. Joel spent time and got nothing; the developer wanted to spend time doing something that would probably speed up the build.
Except that he didn't "get nothing" out of the exercise. As he expected it would, the new drive did provide significant speedups for a variety of tasks and will undoubtedly improve his productivity enough to have been worth the time and money he spent on it. As it happens, it didn't improve the build speed specifically, but so what?