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
I am sorry about this blog, but anime as in japanese cartoons made in japan are under attack by western moral puritans, because it doesn't adhere to their moral standards. This strikes me as a very imperialistic mindset, not everyone has to adhere to our values.
Set: Purplesmart, Yellowquiet, Cyanfast, Orangehick, Prissywhite, Cocainepink Twi: Twiggles, Purple Autism Pinkie: Ponk, Ponka, Ponka Poo, any other of so many mutations of her name RD: Rapidash Celestia: Sunbutt Cadance: Candy Ass
You can also just add "horse" to any of their most outstanding features. EG Bughorse, Applehorse, Dresshorse, THOTHorse, Sunhorse, etc.
Dashole
YellowQuiet
FashionHorse
Ponkers
ApplePone
Sunbutt
Moonbutt
Candyass
ShimSham
GlimGlam
Spike
Trickymoon
DustySpark
Skittles
PineApple
BlueFast
FlutterButter
DressHorse
AppulHorse
Ponk
Pink party pony
Set: Purplesmart, Yellowquiet, Cyanfast, Orangehick, Prissywhite, Cocainepink
Twi: Twiggles, Purple Autism
Pinkie: Ponk, Ponka, Ponka Poo, any other of so many mutations of her name
RD: Rapidash
Celestia: Sunbutt
Cadance: Candy Ass
You can also just add "horse" to any of their most outstanding features. EG Bughorse, Applehorse, Dresshorse, THOTHorse, Sunhorse, etc.
Bubbly - Derpy/Ditsy/Muffins
Tilt - Berry Punch
Garbage Swan.
Chicken.
Toilet Sprinkle.