LogFAQs > #912194482

There are a few well-established reasons why a character like Aqua would do poorly.

First, her game is relatively low status within its series. There are a lot of people who only played KH I & II and never bothered with the "spin-offs." This limits the size of her audience. She's also only one of three player characters in her own game, which further reduces her individual prominence. It's easy to imagine people playing KH and never encountering her, but that can't really be said of people playing Xenosaga and KOS-MOS.

On top of that, voters here seem to be pretty apathetic toward Kingdom Hearts this year, judging by how poorly Sora and especially Riku did.