The impression I generally have of My Little Pony: Friendship is Magic is that it possesses attractive qualities similar to anime, especially when it comes to the more episodic types of magical girl anime. The way MLP respects its assumed younger audience while presenting a variety of characters with fleshed-out and admirable personalities who show many valid ways for girls to be girls and more generally for people to be people reminds me most strongly of Ojamajo Doremi. However, it is the case that not every MLP fan is an anime fan nor vice versa, and it is even the case that some anime fans found themselves more attracted to My Little Pony, undergoing a transformation from otaku to brony. While this could be argued as a failure of anime to retain its audience, and sometimes fingers are pointed at whatever current trend there is, I think it is important to not just look at what anime “had then” and what it “lacks now,” but to also consider the possibility that different anime fans came to anime in the past with varying expectations and areas of adaptation.
Picture two anime fans of the same show who love the story and the characters equally much. The first fan loves the fact that anime is from Japan. It’s different, perhaps even exotic, and to view animation from another country with its own tropes and cultural assumptions and elements is part of the fun. He’s not necessarily a Japanophile, nor does he think that things are better if they’re from Japan, but the fact that it isn’t his own culture adds to the appeal.
For the second fan, however, that cultural difference feels more like a barrier. Rather than it possessing an inviting quality, the culture gap is something which the second fan feels he must work through in order to get to the story underneath. Certainly this fan genuinely enjoys this anime, but if he could get the same show only with the cultural elements naturally familiar to him, then he would much prefer that.
There’s plenty of middle-ground between these two types, but I think this hypothetical scenario is one example of what has happened with people who might have been anime fans but aren’t, or at least anime fans who have found greater resonance with cartoons which are not anime. My Little Pony is similar to Ojamajo Doremi in a number of respects, but MLP assumes an American audience first where Doremi assumes a Japanese one, and having the characters behave in ways more culturally familiar can have a significant impact on the connections people make with a show, even if it were basically the same work as the one that is less culturally close. This can even be as simple as information and access just being easier in your own language.
I can’t find the source, but I recall at an interview or a pnael for Avatar: The Last Airbender and its sequel The Legend of Korra, the creators stated that when making the series, they specifically had their Korean animators look at American body language and mannerisms. Like MLP, Avatar is a show which bears similarities to anime in a number of ways, but this cultural consideration was seen as a way to convey some of those “anime-like” qualities to people who are not necessarily receptive to anime, and perhaps by extension, those who are tolerant of anime’s differences but could do without them either way.
This is not an indictment of the first fan for prioritizing Japan too much, or the second one for not being open to other cultures, nor do I think that this explains everything about the landscape of fandom between anime and other cartoons. There is plenty more to discuss, including fans of both anime and American cartoons in other countries (including Japan!). Instead, I wanted to just bring up the idea that fandom can be quite a malleable thing, and that we may assume there are more connections within a fandom than there might actually be.