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
Cadence
Wallflower blush
Fluttershy
Derpy
Fluttershy
Lemon Hearts.
Why not the canon giantess, Cozy Glow?
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All your reasons?
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Unless I make her adult then yes, but otherwise no.
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Have not seen her big yet.
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To make anon her chair
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She's my favorite, and she'd make a very cuddly and gentle giantess
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Future Flurry?
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Because a giantess that everyone overlooks and forgets?
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Fluttershy is my favorite. And I think it has been awhile since you've done giant Fluttershy.