I used to check some of the /prog/ related channels on Rizon, and other public networks, they are all filled with complete imbeciles.
I'm afraid the IRCs that aren't composed entirely of retards are the small ones that aren't "public", and surely someone in these IRCs wouldn't want to compromise their environment by sharing it with no discretion.
The lowest quality people are the most persistent when it comes to IRC. The people who are actually knowledgeable are not on IRC constantly, they're programming, or studying, or doing productive things. Therefore, it follows, that all public IRCs will eventually be overtaken by persistent retards.