TheOrb said:
Because it is a children's show and not supposed to be taken seriously. Game of Thrones (from what I can gather, as I have neither read nor watched them) is an, adult, serious series that is suitable to be deconstructed. MLP is a technicolour children's show trying to educate children on how to get friends. It's mundane and ridiculous at the same time. The high-pitched voices don't help either.
My friend, you haven't lived until you've deconstructed a children's show. It's fun because it isn't just "a show for children." It's "a show for children
conceived and written by adults." One thing I've always found fascinating is deconstructing the approaches to getting children's attention some shows take. For example, take a show like the Suite Life of Zach and Cody. The whole show is centered around "shenanigans" that start small and progressively get more ridiculous. While the show tries to ground itself in reality with a semi-plausible setup, every episode is an exercise in stupidity and ridiculousness that is insulting to any child half their age, nonetheless one that is actually their age.
But a show like MLP isn't based in reality, and so the more ridiculous shenanigans are just a bit more forgivable. Not only that, they lend themselves to a lot more nuances within their art. For example, in this song:
There are two distinctive musical things going on, here. One is called a deceptive cadence which is sung by the evil pony at the beginning, and the other is an authentic cadence, sung by the nice pony at the middle and end.
This is important because the evil pony at the beginning is an evil creature disguised as the good one, and in this episode she's been disguised as the good one and tricking everybody (including her fiance) into thinking that she's the real deal. The good pony's name? Cadence. So the fake Cadence sings a deceptive cadence chord progression, and the real one sings and authentic cadence chord progression. True story. [http://www.equestrianbeat.com/2012/04/daniel-ingram-is-genius-kinda-old-news.html]
This sort of thing is why MLP has attracted the attention of so many adults. While a lot of it is fluffy and transparent, the creators often imbue something a little deeper and more meaty.