If you believe the problem is with the Linux kernel, perhaps you should take up your case on a more appropriate mailing list?

Python's socket module is a fairly low-level module, as it's just a thin wrapper around the corresponding operating system calls.  Anyone using it has to be prepared to deal with a certain amount of exposed operating system details.

If you want to use TCP KEEPALIVE on Linux, then just call:
    my_socket_object.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)

Most non-trivial applications use select() or poll() to avoid blocking calls and do their own timeout-checking at the application layer, so they don't need KEEPALIVE.