I don’t know, it’s always baffled me.
The second that a completely unimportant character like Chinjao had it should have been a sign that Oda was just going to toss it around like Toriyama tossed around being a Super Saiyan.
(And you could argue that started a few chapters earlier with Doffy getting it. Or even go back to Hancock).
There was this perception from before the timeskip it would just be the Yonko, a few important Ds, and one or two others that would have CoC, and people just were unable to accept this wasn’t the way Oda was going and kept coming up with these baffling “rules” to stop people having it. “He cried once, he can’t get it!” “He doesn‘t lead anyone!” My personal, dumbass favourite of “Marines can’t have CoC.”
When really the only two things that mattered was
-Ray saying most people who had made a name for themselves have it
-Chinjao saying it’s all over the New World.