I guess it's an unfortunate consequence of having a captain like that. They try to be like him, but in the end very few indeed ever can. And as if that wasn't enough, Kenpachi also acts like nothing else but enjoying the fight matters. To really live succesfully (as a shinigami) with an attitude like that, you need to be a one-in-a-million asskicker to avoid failures. People like Ikkaku should realise that, and that there's only one Kenpachi.