“Could care less” is stylish and zingy. “Couldn’t care less” is lumpen and earnest. Given that everyone knows what they both mean, one should always use the former.
I could care less = there is more room for me to not care..or I care some...
To people that read words, it is a big difference...imho
Bovine scatology. It means just the opposite of what the speaker/writer is trying to express and makes the speaker/writer look stupid.
But since it’s stylish and zingy that makes it just dandy.
/s