I would guess the problem with sockets is in the whole creation process. Instead of just calling open() on a magic pathname (like how you deal with devices in Unix), you call socket(), then bind()/listen()/accept() on the server side, or connect() on the client side. Luckily they didn't totally screw it up, and it's just a regular file descriptor after that point... except on Windows, where they did screw it up.
