Kaido knows he is not joy boy .
He waited joyboy and he believed he will achieve what joyboy failed with his way. Therefore , he looking for joyboy to prove himself .
Kaido is dirext enemy of luffy in that regard . Zoro was humilated one times by kaido . And zoros intention disapperad after rooftop . He did not even say one sentence related to kaido . Also , why did zoro go alone if he go kaido ? All strawhats are awake and have better conditions than zoro .