Yes, I think it is.
I do not
> see the centrality of the everyday/scientific distinction to this
> general principle.
If it is not central to understand the distinction between
everyday/social concepts, it was in fact very helpfull on depicting such
distinction: Wasn't through that method that members of the Russian
Cultural Psychology School discovered/exposed "the role of words and
the character of their functional usage in the process of concept
formation" (Vygotsky's "Thinking and concept formation in
adolescence" In: Veer-Valsiner's THE VYGOTSKY READER, P. 209)?