I think it might have something to do with the show having a lot more competition now a days. The reason this show picked up so many of us adult fans in the first place was because it is not insultingly written, has more of an adventure bent to it then you’d expect from the franchise, has witty writing and an extremely likable, well developed cast, and it came into existence at a time when those qualities were in pretty short supply in cartoons.
I think the show is facing a lot more competition from both Gravity Falls and Steven Universe now that both those shows have really begun hitting their stride. They have a lot of the things that made us like ponies, and a few things they do better then it.
