CrimsonKidCK:
Well, my northern neighbor, there was actually another point beyond the obvious one I was making, that merely reversing names and pronouns might not work effectively in altering an M/F spanking account into an F/M entry to the current Challenge.
I find this a quite interesting question and have tried to read the challenge entries with it in the back of my mind. There are (rather obviously) no entries that would work as M/F-stories with just a change of clothes, names, and pronouns, but there are some with a basic idea that could just as well have been turned into an M/F-story with basically the same impact. There are also a few that might not work as M/F-stories, but that could perhaps have been turned into F/F-stories. The rest seems to be intrinsic M/F-stories that cannot easily be turned into something else.
There seem to be several reasons why F/M-stories are inherently different from M/F-stories, most of them having to do with the ways we perceive men and women. Here are a few:
1. The idea of a man (often big and strong) being dominated by a woman (often petite) seems to be erotically charged in itself - to the degree that some of the stories seem to have this situation as its only point of departure.
2. Dominatrix-stories play on female sexuality in a way that a story with a male Dom cannot replicate.
3. A number of stories in the challenge have plots where a group of women gang up on a man to give him a good spanking (often his wife and her best friends). It's possible to imagine a role reversal where a group of men gang up on a woman, but it would have to be written with great care to avoid an unpleasant feeling of assault. In addition, it's a plot that would probably fail to appeal to most men as they would have a feeling that they should be able to deal with their wife on their own. There are definitely fantasies and stories where a woman is spanked by several men, but I think they tend to be more exotic, as stories about women abducted by a group of soldiers or pirates, or kept hostage by a primitive tribe.