Hrm, perhaps I should have been a little clearer. When I said "for the sake of it" I meant that. Posting a picture that one considers "failed" or "bad" for critique can be a great learning tool, though I feel one gets more out of it when one feels there's something that could have been done better, but either one doesn't know what could have been done better, or has an idea but isn't sure about the details (like, knowing your exposure is off but not knowing how to correct it, as a random example). If you already know what you could do better to improve the image, much of the criticism you get will be redundant.
Sorry for any confusion. I wasn't trying to discourage putting up shots for critique, I was just using the moment to note as well that it's generally a good idea to showcase your better/best work. Canonian saying "I just threw it in" was what prompted my response, for better or worse.