Earlier quoted context omitted.
I couldn't care less if there's a group of people misusing the phrase, logically "I could care less" means the exact opposite of "I couldn't care less". The majority of the world is not American, and presumably the majority of Americans don't use the incorrect phrase, so why should the rest of the world cater for a minority within a minority by putting their butchered phrase on equal footing with the correct phrase?
And logically, flammable and inflammable mean the exact opposite, but here we are.
Still, I do find "I could care less" to be less of a contronym and more of an "Americanism". I'm quite used to it by now, and shall thereby sanction its use.