I have no idea how m-preg fictions even exist. Maybe a lack of sexual education for teenage (american) writers? In any case, the very definition of "female" is that it is that part of the species that bears children. I'm not sure if the writers of these are aware of the logistics of conception and birth, but the two or three times I got far enough for that I didn't get the feeling they were. Maybe Mary and Jesus are to blame? Who knows.
Mary Sue is just boring, not really a hate. It makes me give up a story fast though.
Just some examples that really get me to bang my head against the wall: (not sure these are tropes? what exactly are tropes?^^)
Harry Potter - Marriage Law - I mean, the concept isn't that far off in terms of fanfic ideas, there is great potential for former enemies to actually work together against a government trying that sort of thing. Only, no writer goes that way! It's more like, "Hey, the government made some stupid law, we really hate it and we really hate each other but, oh, we're suddenly in love." -and that every time I make the mistake to click that sort of fic. It's generally horribly narrated.
Harry Potter - Inheritance - Harry inherits a ton of money/ titles, and all he does with it is going shopping like a kid in a candy store. If I had Voldemort after me and I inherited anything between 20 million - 50 billion galleons, a cool wand and a 7 lock compartment trunk would be the least of my worries. Hired Muscle, buying influence in the government, whatever... it's super rare that a writer actually ever uses the money from Inheritance. Same with the titles/government votes.
Something that's so dumb it's almost funny is a Harry Potter Non Magic AU
It's like... just go call it original fiction and simply use other names for you characters...
Harry Potter Magical (creature) inheritance stories are not my thing, but if it also includes having to marry and have sex with your magical creature mate who just so happens to be a very specific person... that's just .... It basically screams "I can't write proper character development and romance so... magic! the characters I want together have no choice!"
Meh. Maybe my expectations are too high...
I don't read much outside of HP, (though I could probably go on endlessly with these HP abomination of plot ideas).
Anyway, great to know that this sub forum exists. Hi everyone