[derefr]

C++ is used in many non-low-level domains simply because of performance, due to the many kinds of zero-runtime-overhead abstractions it offers. There are e.g. popular game engines written in C++. LLVM is written in C++. Some DBMSes are written in C++. Etc.

C# overlaps C++ in all these “performance-sensitive high-level code” domains.

[waterTanuki]

Given the topic of the thread is DARPA it's unlikely they're going to benefit from the type of overlap C++ and C# have in game engines or DBMSes.