Just think about it, you and a couple of friends are watching classic South Park or something edgy. And then, some person comes who's not even a fan of it, demands changes (censorship) or outright turns off the program. Just why do people do this? Why do they ruin everyone's fun?
Seriously, they are. This is by far the most important issue, if they made their asses fatter it would improve viewership. If they made the ponies thicc prudes would complain, which would only draw in even more viewers. Twilight Sparkle, the protagonist of the series has a fat ass, and her teacher Princess Celestia, who's ass is even fatter.
The main reason is uncanny valley. When something looks human but not quite. A perfect example would be a robot trying to mimic being human, it looks unsettling. It's somewhat insulting towards the ponies, you have Twilight Sparkle there a beautiful unicorn and you can't embrace her just because she's not fully in human shape, even though she has all the qualifications to be a sapient-minded
What if you continue the story of Big Horse Women Need Male? but this time please try to give more plot, development, interesting plot turns, good use of the characters, good ideas, so that it is not only sex (I do not see any problems) and finally as a personal request please give it protagonism to the two sisters and to Celestia give him a very maternal personality with the protagonist being she who breastfeeds him the most.
Get inspired.
Why not some Christmas booty?
Music maybe? I got a lot of inspiration from story driven songs
What if you continue the story of Big Horse Women Need Male? but this time please try to give more plot, development, interesting plot turns, good use of the characters, good ideas, so that it is not only sex (I do not see any problems) and finally as a personal request please give it protagonism to the two sisters and to Celestia give him a very maternal personality with the protagonist being she who breastfeeds him the most.