[throwaway984393]

If Operating Systems had TLS built into the TCP/IP stack exposed by the kernel/system, you would never need to shim it in anywhere. You would just make a system call and use an open file descriptor/socket. One of the many programming-in-1970s-style things we still have not fixed.

But 1) kernel hackers won't implement it, 2) app devs are too possessive of their stack/codebase to just use one standard implementation/interface, and 3) security people are too paranoid to leave something "so important" up to the OS so they'd rather everyone implement it poorly/fragmentedly.