Yeah, but I object strongly to the "invariably" in the original quote because it happens not to be true. I know lots of writers, even published ones, who underwrite the first draft. Personally, I tend to leave out descriptions on the first pass, and so on the second pass when I take out the excess words, I also add descriptions, and the end result tends to be about the same length as the first draft. This isn't to say that learning to "omit needless words" isn't a good idea, just that it isn't always what is needed.