I doubt that.
The parts that actually somewhat work in XMPP would be fairly straightforward to add to IRC (mostly related to persistence and identity). From there the question is where you'd want to take it, not what idiocies XMPP fell for. I.e. the task would be to do it right, not to imitate a broken protocol.
Just compare http://www.ietf.org/rfc/rfc1459.txt to http://xmpp.org/protocols - where the latter isn't even the full story.
And then tell me with a straight face the complexity is "inherent to the problem". No. It's not.
IRC handles very similar problems to XMPP already (and then some that XMPP doesn't have) and the specification, in its entirety, is only 3643 lines long. Extending that for distributed, message-persisting operation would not bring it anywhere near the insanity of XMPP.
Naturally that's an academic exercise, nobody would actually re-shape IRC into an IM system that way. However, when cherry-picking concepts for a new protocol then IRC should be high on the list, and XMPP rather low.
I've actually written IRC bots mostly from the top of my head.
The protocol and semantics are really simple.
Type this into a console near you:
nc irc.freenode.org 6667
USER foo bar batz boo
PRIVMSG #testchannel hello world
PRIVMSG test345 hello self
I'm not sure what you mean by fractured. Like every protocol it has a few rough edges, but those are nowhere near the semantic nightmare that I witnessed when trying to dabble with XMPP (which admittedly was more than a year ago).
How long did it take you bring your client into a reliably working state? And have you tried to do the same with a XMPP client for comparison?
As said, I didn't mean to claim IRC is perfect - nothing is.
But if you think the differences that IRC networks have introduced are problematic then I invite you to try and build a most basic jabber client.
However, I think it's a big mistake to claim IRC "scales amazingly well". The biggest IRC network today has tens of thousands of users (at the moment, freenode has 64000, undernet has 58000, and EFNet is down in the 32000 range) and the IRC networks are constantly suffering from breakdowns from overcapacity. Compare this to Skype, Facebook, or Gmail, with tens of millions of concurrent users.
IRC was a great protocol in the 1980's, it's been dead for a while, just there are no good replacements.
The point I was trying to make is that IRC would be a more sane starting point than XMPP. Even despite all the shortcomings you mentioned and some more that you didn't. And even despite it being a strictly centralized design that would require more server-side changes than XMPP to turn it into a distributed system.
I'll lean out of the window and even claim you could make a distributed IRCd backwards compatible to existing IRC clients, as far as the core business of presence/state, chat and group-chat are concerned.