The fact I "understood the intent" doesn't make it grate any less, whenever I set this phrase misused time after time by Americans. "I could care less" is literally the opposite of the sentiment you are trying to express.
Thanks for your feedback. However, I’m going to stick with Webster on this one. Let’s also not forget that English has always been a hodgepodge of language mashups and slang.
https://www.merriam-webster.com/words-at-play/could-couldnt-...