For someone who tries to write in a foreign language, as I do, criticism is useful, and the more public the better because it calls for other advices from different sources. So you know how your text is perceived by the average reader, not just by a single individual (pleonasm!) whose tastes and competences may be too personal to be very informative.

In my own language, on the contrary, I don't need external criticism; I know rather well to assess my achievements: if I am satisfied that means it must be good for I am the most ferocious censor I could be confronted to.