Comedic irony.
Most Fluffy lore originates from jokes as it evolved from fan works about MLP “But everyone is just pets” in the same innocent vein of Muppet Babies.
Handwaving whatever happens in your story as not having any human interlopers no matter how it goes because the little incontinent horses are legally soap was silly enough to fit the general mood then.
It lingered because it works as well in the opposite direction. A world so serious that the insanity of real life, like people ignoring public health crisis and doing whatever arbitrary stupid thing they want while corporations barely pretend not to do awful shit, is just thrown against plague-spreading famine-causing Jurassic Park Furbies while corporations and politicians shrug and say “Soap” improves things.