Well, it's not really the curse, because you don't have to actually read it. But sometimes you see the summaries and you go 'oh my god. kill me now.' And want to send money to the writer for tutoring in basic grammar or therapy.
The problem is that there isn't a fandom, pairing, non-pairing, character, whathaveyou that I've encountered without it. It's universal as far as I can see. I am willing to be proven wrong about this, but for every one I've encountered there's been stuff that wasn't just rubbish, but was horrifyingly terrible in a way that made you think we might be facing the end of the English language. But I assume it made the writer happy in some way and probably in about three years they will find it again and think 'Er. Right. Probably that wasn't such a good idea.'1 But as the internet has a surprisingly long memory it will pop up again somewhere. Not that I'd know anything about that. Ahem.
I assume the larger the fandom, the larger the amount of fiction and thus the larger amount of rubbish out there. I don't actually believe that certain types of stories are more likely to produce terrible fiction than others. Or vice versa. Well, except for Mpreg. And stuff with babies.
Having said the last, it's true I've actually seen fiction with babies where it works. Mainly because the writer doesn't think that babies solve everything and goes for the knife in the heart approach. Can you tell I don't like babyfic? But there are people out there who do and I assume it does something for them and probably they could link me to tons where it actually makes sense as a plot device. 2
There are personal dislikes I have: rapefic, babyfic, mpreg (a genre whose very existence fills me with bafflement), incest. And anything which is clearly written for the sole purpose of bashing a character so you can have your one true pairing ride off into the sunset (and this involves even pairings I ship). There are characters I'm not particularly interested in and the same is true for pairings. But I don't actually assume my lack of interest (or even dislike) makes the fanfic about them awful. Well, unless it involved Mel and the Doctor, because, well, it's Mel. I do not think you could write anything good about that woman.
But the point of this post is, well, do you think that there are fandoms that are likely to produce more terrible fiction than others? Better fiction? I'm guessing The My Little Pony fandom probably is not going to attract the good writers, but beyond that I don't know.
1I firmly need to believe that people learn from experience. So leave me with my illusions, please?
2 But I still would not read it. Because, well, babyfic.
ETA: In the poll below I think it is very sad that Mary, Queen of Scots has not garnered a single vote. Even Catherine Howard got one! *cries for poor Mary*