Luffy wants to be the PK, wants to defeat the Yonko, defeated rulers, has another secret key goal, can turn people around him into his allies, seen as a deity-ish person...
Zoro wants to be the WSS, uses Oden's sword, will be seen as a deity-ish person after ZKK...
Yamato is mimicking Oden, seen as a deity-ish person...
Usopp wants to be a brave warrior even though he's a coward, claims to be the King of Snipers, claims that he's a CoC user, claims to be a captain of a large fleet, seen as a deity-ish person...
Nobody else in the crew aside those 4 have the qualities required for CoC...