I seldom use that technique. Almost never. I agree with @theducks and @JSWolf: it should be avoided.
But if I have 52 hypertrophic css files in a fiction book (one for each chapter, I did not check if they are all equal but I think they are)

with no particular formatting, except for titles, the time I would loose is more important than a clean work.
So: Epub to Epub with "remove spaces from paragraph" and 1.5em of indentation et voilą.
ps: I would like to know who is that made this horrible work.

(may be the author itself).