I would posit they were written down as falling undrer "Chaotic Good" because Gygax lost whatever thoughts he had about the more Elric inspired Law-Neutral-Chaos, and didn't think through the expansion with anywhere the depth of the philosophers or even the writers of 4e.Exactly! Chaotic Good seems completely bonkers, and I don't think large groups of humans can pull it off. Yet one of the most important demi-human groups have been canonically Chaotic Good since 1e. I think that's interesting, and I came to this definition precisely to explain the behavior of elves. The result is weird, and I like that.
Part of the problem feels like there is an extreme difference between tendencies of people and the extraplanar extremes of the far realms, the demons, and entropy. And trying to use the same word without modifier for both seem like it might be sub-optimal.
Stolen from another post...
LAWFUL - Following ones guiding code and working against CHAOS is the most important thing ("extraplanar lawful beings")
Lawful -Tries to always follow their guiding principals, but may have other over-riding concerns ("lawful")
lawful - Likely follows the rules unless they're standing in the way, but doesn't angst over it ("lawful tendencies")
chaotic - Chafes against the rules but doesn't go out of their way to break them just for the sake of doing so (unless they're annoying) or trying to sow randomness ("chaotic tendencies")
Chaotic - Flouts the rules and doesn't follow a personal code. ("chaotic")
CHAOTIC - Overthrowing the order - both local and universal - is the most important thing. ("extraplanar chaotic beings")
Even then, would Chaotic have the factions of the Far Realms, Demons, and Ultimate Entropy as competing interests? Should any of the extraplanars (except maybe CHAOTIC EVIL) be allowed only one all-caps descriptor?