I think people are confusing Nintendo characters having good personality with just being well known characters that people like. Domesticated animals have more entertaining personalities than a Nintendo character. I'm not kidding. But Nintendo games have never really been about having a good story so that's the reason. It's always about the gameplay.
I like Sony and Nintendo, but I like a lot more characters from Sony games over characters from Nintendo games just because of this. I like Nintendo characters based on them being from a lot of great games, while I like Sony characters even if I only like one game, a character can still make a good impression. On the PS3 but not a Sony game, only using this as an example of a game I don't like, I didn't like Hyperdimension Neptunia Mk2, but I really liked IF as a character. I actually purchased and use IF as my PSN avatar.
