I take your point, but I'm not sure you're really taking his. As another data point, I just did a find/xargs-grep across my "~/codebase/3p" tree, which has ~5500 .h files for projects ranging from MongoDB to Ruby and Python to OpenSSL to valgrind. Virtually all of them have nested includes. Many of them are components of mission-critical software.
> In all my years writing C, I have never seen a C/C++ header which does not include the other headers it needs in order to compile cleanly.
> He's right; nested includes are a modern C idiom.
No doubt they are found a lot. The request was for counterexamples. Fashion/style vs engineering practice assertions may be passing like ships on a nighttime C here.
>...for projects ranging from MongoDB to Ruby and Python...
Python....why, even Tim Peters asserts that "Flat is better than nested"...wink...
He's right; nested includes are a modern C idiom.