it's what has happened once people closer to our age has gotten into writing for children's shows. i have noticed that though these shows come on cartoon network and "the hub" or nickelodeon, they arent quite like kid shows of the past.
my niece was watching that, and it seemed a little too self aware for a typical kid show. similar to regular show, adventure time, spongebob, etc. this stuff is made to pull in as many adult fans as children. the only thing that is unique about bronies is the fact that the show is ostensibly for girls, but if they were wearing the white fuzzy animal ear hat that finn from adventure time wears, they would still be ridiculous but not as gay looking.
it looks like the purely kid show programming has moved on to the "jr" television block of shows aimed at preschoolers, but even that has been invaded by the adult hipster fan favorite like yo gabba gabba