No, not at all! At least not in an absolute sense. But what I mean is that writing in C naturally tends towards writing more special-purpose, bespoke functions

No, not at all! At least not in an absolute sense. But what I mean is that writing in C naturally tends towards writing more special-purpose, bespoke functions because you can't lean on the existing, general-purpose functions of C++ (nor language features). I agree with you about the title, but I also think that if you fix the title the author is making a good point. It's not groundbreaking, but the move "down" from C++ to C does run parallel with the move from more general purpose to more special purpose, in a lot of ways. C dominates embedded after all.