Why? This is a failure of the CSPRNG. What "not implementing your own crypto" usually means is trying to cobble together primitives like AES, RSA, and some mod

Why? This is a failure of the CSPRNG. What "not implementing your own crypto" usually means is trying to cobble together primitives like AES, RSA, and some mode of operation (and, if you're lucky, there's a MAC algorithm in there too), which would still probably have been horribly broken in some way. That's completely orthogonal to this issue. Are you insinuating that explicitly seeding the CSPRNG with information from the OS' CSPRNG is somehow a bad thing, or that it is frowned upon, or that it constitutes "implementing your own crypto"?