I missed this, very interesting read. He's not entirely wrong.

But why are these protocols frozen? I've never developed one so I may just be ignorant of the challenges there, but if, for example, I wanted the XMPP protocol to be able to work with rich media, what's stopping me from updating said protocol to work with rich media instead of relying on optional extensions? In my mind, users of the protocol will receive the update (if they choose of course), thereby making the feature a default for the protocol that isn't reliant on extensions.

I admit I don't fully understand why protocols are frozen in this way, even though I agree with the author that the ones we currently have are definitely frozen. Any insights appreciated!