There is a lot to respond to in this thread.
First I should probably confess, at the risk of offending quite a few authors, that I tend to enjoy only a very narrow range in spanking stories. However, while that range excludes a lot of popular spanking themes and scenarios, it also includes quite a bit of variety as long as the central issue of willing submission is explored. So, for example, while I tend to avoid child discipline stories, I have enjoyed a few that clearly depict the victim as complicit in, and even desirous of, their fate. The same is true of M/F, F/M, M/M, F/F, etc. If the story involves a believable, dynamic with a willing victim, I will enjoy almost any dynamic even though I prefer F/M. However, this is still subject to good content. A sequential narrative does little for me regardless of the detail. 'This happened- then this happened-and then this happened' ----(yawn). A story needs a point.
As for believability, I would have to agree with rollin. While I do encourage my own willingness to suspend disbelief when reading spanking fiction, that willingness still only goes only so far. Just because a popular majority is willing to be entertained by the implausible does not mean that such tolerance is embraced by me. Enjoying the implausible is fine in the context of fantasy subjects. ( For example, I happen to love the whole comic book superhero genre....and much of that subject is overloaded with unrealistic ability and situation.....but then again there is no actual, real life Spiderman to pattern a more realistic story around. The subject exists only in fantasy.) But for me "spanking" isn't the same. Living with spanking is a very real and enjoyable fact for me. I know plenty of people who do it. Therefore I know it can be explored quite realistically, and I want a story's characters to come across as real as the people I know, and the spanking situations to come across as real as the situations I've been in or have been told about.............even if the situation is stretched a bit for variety. Stretching I can overlook. Total fabrication with no tie-in to realistic observation of people and how they act? Maybe if it is a Spiderman spanking story.

If I return to the original question posed in this thread though, I would have to say that my least favorite theme would have to be the period home or school discipline scenario. These situations invariably contain my two biggest turn-offs: underage victims & nonconsentual punishment.