It sounds dickish, but honestly, they probably won't. It would be a lot of work to send out personalized emails to every contender telling them why they didn't win. That goes for any sort of contest. Besides, it's not like "losing" means you did anything "wrong". Sometimes you just don't win. Especially when it comes to writing contests where everything is up to both personal taste and publishers' preferences.
If you're legitimately looking for honest criticism, I suggest just asking for it in a thread or from people who do just that