Other hypothesis:
the wife factor: yes it's a Leica, but it's cosmetically very bad, so I paid it half the price. Do you think I would have ever bought a Leica in good conditions?;
the criminal factor: less likely to undergo an armed robbery;
the political factor: your insurrectionalist-anarchist friends (or Marxist-Leninist, or whatever) will not consider you any more greet-worthy if you go around with a properly shiny Leica.
the religious factor: if you are a pastor, your "sheeps" will begin thinking they pay you a bit too much for the sermons you deliver; or you happen to be a Tibetan monk and your Abbot is not going to compliment you on your purchase of a new shiny Leica
etc.
Well, it devalues it so it could be a nice purchase. Mechanically could be much better than cosmetically.