Edit: The answer is, "Yes, Henry Churchyard," for those who TL;DR.
The idiom of knowing nothing and caring less is still active, witness the Tim Rice lyric:
You know nothing about me and care even less
I ought to have used Google instead of DuckDuckGo to learn:
The idiom "couldn't care less", meaning "doesn't care at all" (the
meaning in full is "cares so little that he couldn't possibly care
less"), originated in Britain around 1940. "Could care less", which
is used with the same meaning, developed in the U.S. around
1960. We get disputes about whether the latter was originally a mis-hearing of the former; whether it was originally ironic; or
whether it arose from uses where the negative element was separated
from "could" ("None of these writers could care less..."). Henry
Churchyard believes that this sentence by Jane Austen may be
pertinent: "You know nothing and you care less, as people say."
(Mansfield Park (1815), Chapter 29)
So a nominal answer to my question is, Yes, others have thought so.
This saying was common rhetoric:
I ask you to vote for George Stoneman for Governor of California, ...
These men I know to be honest; I will vouch for them. The others I
know nothing about, and care less. (1882)
(The orator goes on to say, "It is not right to attack Stanford and Co. while we are willing to uphold the system." Which applies today equally in Silicon Valley.)
Since idiom thrives on simplification, it seems at least possible that "Blah, blah, blah care less" finds a convenient formulation in "I could care less", obviating the need to establish a preceding clause.
"Whatever. I could care less."
One could suggest: "I could very well be one of those who nothing about it and care less." The positive sense of "care less" is retained from the underlying idiom.
The endless discussions about grammar and logic may be beside the point.
As Austen tells us, all the meaning is conveyed in the tone.