Although this is definitely not how people usually use it.
The entire spirit of the phrase is to denote how little someone cares about something. So if you say they could care less, that implies they care a tiny amount about it and CHOOSE to care that much. I don't see how that could ever replace the original phrase and still make sense.
"I could care less! (Yet here we are discussing it to death.)" or "They could care less... (less than we do / less than all this discussion suggests they might care)"
^ I think that's essentially how most people use it, mechanically, without thinking about it as much.
When I say it, I usually either mean it that way, or something along the lines of "I could care less! (And I wish I did!)"
That is the dumbest thing I have ever read.
Please don't post things like this to HN. (Broken windows aren't allowed, even on the bikeshed.)