Why isn't encryption baked in by default? It's optional from what I can tell. I don't know how you can design a new protocol and not include encryption.
It's not a new protocol.
So I'll reframe my question and ask: Why isn't TLS a base extension?
We strongly believe that the future of IRC is TLS-only.
There have been lots and lots and lots of discussions about that, but considering it’s just an extension to the existing IRC protocol, it’s not that easy.
But it’s easily possible to enforce SSL over IRC already.
IRC was new in 1988. It's 28 years old protocol now.
This is like the email situation where encryption options exist, but it's too hard for mere mortals to use. If it's built into the base protocol then there's a chance that clients would implement the standard and actually use it.