Even if you hated a character, why would you get rid of him? Isn't it better to have that feature there for those who do like the character than not have it at all? Remember, while we have to replace characters to install 'new' ones, if the team adds a new character they won't have to take out old ones. They can extend the list rather than change it.
Besides, I don't think you could have a DBZ mod without the characters we have now. Even if you hate Krillin, you'd surely have to agree that he should still be in the game because he's always in the show. Likewise, if you hate Frieza, you surely can't dispute that he deserves a spot in the game for being such a key figure in the series.
As a theoretical exercise it's fine, but don't make a habit of listing characters you hate and want to get rid of it. It shouldn't work like that. More = better, less = worse.
Still... if I had to, I'd take out Vegeta and replace him with Babidi. Go wrinkly lemon wizard!