I agree with most of your post, but something I do want to say is that a show can and always can be marketed towards boys or girls. There are some things that appeal to girls more, and things that appeal to boys more. Not all boys or girls, per se, but each gender does have preferences in tastes. Most boys seem to like action and robots. Most girls seem to like horses and bright color. But that of course doesn't mean a gender can't like things that (usually) appeal to the other.
With that said, I'm honestly a bit surprised to learn that little girls is still their primary demographic. Sure, I know the show was made with that demographic, but I honestly believed they'd moved on to "teenage show watchable for little girls." Stranger Than Fan Fiction anyone? I didn't feel like that episode was made for 6 year-old girls. It felt more teenager-y with all the snark and sarcasam going on. Heck, I wonder how many 6 year olds, male or female, know what fan fiction is lol.
But then we had Cart Before The Ponies right after, and yeah... that wasn't teenager material at all. So I guess I drew that conclusion more from exceptions to the queue rather than the whole of it.