Gabby

Animated TV shows over the last decade or so have been following a certain trend. It would seem, that if an animated show is popular (let's consider for example, Adventure Time–having spawned numerous types of merchandise, comics, and video games), despite having some sort of intended (I use the term loosely here) audience of younger viewers (exampled by what network may pick up a show, like Nickelodeon or Cartoon Network), it grows a larger audience in older viewers as well, the "unintended" audience. What could cause this? Is there a notable trend in TV shows this happens with, like Steven Universe, Star Butterfly vs. the Forces of Evil, and so on? (Important to note the differentiation between shows such as these and those that have an older audience in mind, like Futurama and Bojack Horseman).