Mistakes are good, to some extent, but not in everything. Would you tell someone that unsafe sex is ok, and that one should learn its danger by doing the mistake, catching a STD, and then not doing it again? Would you tell someone that building a bridge without double checking pressure contraints and simic conditions is ok, that one will learn by one's mistakes when the bridge will fall apart? Hmm, so there are some limits to this "learn by your mistakes" thing, right?
In coding, the same. It is ok "to write dangerous or “crappy” code" (Why quote) in personal projects, not in those where life are at stake, eg. airport traffic control or medical software. It is ethically not ok to write dangerous code in these case, and I would say it is the same when your code will have to be read, used, debugged by others. I admire people taking risks, too, like I admire someone eating 50 eggs in 1 hour, but I would not always advise my friends and relatives or coworkers to take those risks. Sometime, most of the time, the reward is not good enough.
I appreciate "Why" writting skills, he is or was an impressive guy, but taking to the letter every of his tweets should not be mandatory on HN, I believe.
Thanks for explaining why and where I'm wrong, if it is the case.
Your example is a little bit over the top. I might have generalized too much but I think that in the context of the discussion you get the point I was trying to convey. There are always exceptions to every rule, of course. I believe my comment still stands, most of the time.