Yes, I have submitted some that are misty hazy or not otherwise pin-sharp - I meant it that way! Its possible they go through some kind of electronic process that just defines it as unacceptable and that's it.
I am also a bit mystified by the rejections - also by some of the acceptances!
Every single one of the images I have submitted that feature fog or mist have been rejected for "Out of Focus". It seems that there is a machine algorithm that looks for acceptable focus, and it reads fog or mist as OOF.... Too bad, since, living here in the SF Bay Area means that I have some nice foggy images.
I just had a blurred lights city skyline rejected even though when I search there are others already approved, I can't seem to find a place where I can ask a question about the photo.