My feeling says it is especially the delight seeking/seeing activity- an orientation on something which lies in the future, a focus on the future-, from which a future (renewed existence) is created. Delight seeking feeds the process of becoming. Seeking delight in sense pleasures, in existence and in not to exist anymore and be freed of suffering.
The second noble truth, is, i think especially about this seeking delight as the most fundamental cause for renewed existence. Hate is secundary and arises when ones delight seeking activity is blocked/frustrated.
In that sense i think craving is not bad as cause. Craving as in delight seeking.