Just as an example, neither the C++ documentation nor its sagely bloggers have ever shown why it is a good fit for, say, systems programming. A really neat way of handling bit-level data is actually in Erlang's bit syntax.
Separately, I spluttered when I realized that Boost includes 2 statechart libraries which proclaim the approach is widely useful, but nothing else in Boost uses it - not asio or its ilk, not the parser libraries, not the graph library.