Lucky Fire, you don't recall Fluttershy's name? Isn't its name "Fluttershy"?
I'm guessing it's because it's supposed to be a children's TV show, HOWEVER it derives qualities from other TV shows that they watched as a child, and thus, it holds a certain quality of nostalgia to it (I've been told that the team who worked on it was the same who worked on Foster's Home for Imaginary Friends, a well-loved children's cartoon during its time, myself included.)
...that's going to be my draft theory for why people like it. Later I might be able to refine it.