I wouldn't say that it failed or people aren't interest so much as SE has failed to add anything or any interest in it themselves. People constantly ask more about it despite SE not having added anything to it for over a year and not putting enough longevity into it to make it well last. If they had put some real rewards in there and/or continued to add stuff probably would have people still doing it. But the rewards aren't worthwhile so the only thing to do is lvl them... which is fun but you can get them all to 99 fairly quickly. The whole cheer system seems like it should've gone to monstrosity instead and in a way it feels like monster rearing as a whole was foisted upon us instead of getting more monstrosity