It was easy for us to say this 15 years ago when a super-compact binary protocol just seemed to make oh so much sense, but now I'm not so sure.

The IRC protocol does exactly what it sets out to do, and there isn't really much over-the-wire overhead for client connections. The only information that's repeated unnecessarily is user hostmask data; everything else is mostly 100% useful.

It could really have only been a bit better if each event was described in a JSON- or YAML-like notation, but this was 1988, not 2008.

Compared to tons of other legacy protocols in use today (FTP!?), IRC isn't all that bad.