If you replace IRC with SMTP the story is very different. IRC has a lot of protocol problems but the biggest one was honestly just not having an IMAP equivalent. IRCCloud is just providing the complementary protocol to IRC. Its existence doesn't necessarily mean that IRC is a bad transport protocol.
IRC has no message storage - so not only it has no IMAP, it has no POP3 either.
And IRC is a horrible transport protocol because it handles errors by dropping messages. SMTP has both message-ids and explicit confirmation response to make sure that as long as server comes up, eventually, the message will be delivered exactly once. IRC does not; so it is simply not appropriate for the cases where each message matters.
