Well that's the thing, they have shown that absolute will can be put to excellent evil usage. They've also shown that red lanterns aren't evil (except at the very least a certain someone), but that because of their nature they can't control their actions anymore, thus creating bestial monsters.
Oh but I would LOVE LOVE LOVE if they did show another red lantern that could control the power and use it in a more heroic or neutral light. Hoping Gardner goes this route really.