To me Animal Crossing is iterative. Unlike any game in the Zelda series. It?s aiming at doing everything the last one did, but better. Hence, there is no reason why an Animal Crossing enthusiast would go back to any previous, lesser version of the same title. The games in this series are meant to replace the previous one, and not form a chain of a consequent series of stories designed to pick up where we last left it.
Okay, this is your opinion on that topic and I respect it. However, just because a new title is meant to replace the old one doesn't mean that everyone automatically enjoys said new title. Even for being the newer title here, New Leaf lacks on things previous games had to offer (for example: unique holidays, the "rude" villagers aka villagers with a better representation of their personality, the observatory, different town layouts, sometimes even villagers that didn't make it into the newer games etc.) and if you don't give a carp on how the graphics looks (what lots of people do out there), you can in fact enjoy a older title of the series even if NL was your first AC game.
(And believe or not, there are people out there who would rather use Windows 95 the whole time than Windows 10, as crazy as it may sounds to you.)