[jasode]

>So your protocols are open and

You're right but in this case, I don't think your criticism is relevant to why they mentioned "IRC". Maybe I misread their webpage but it sounds like they're criticizing IRC. The full blurb immediately after "We grew up using IRC" is about "message fatigue" and "pain of having to skim thousands of messages":

>We grew up using IRC. We’re a team of engineers and designers that hit message fatigue. We’ve felt the pain of having to skim thousands of messages, and we’re building Quill to solve it.

So it's like they're actually saying, "We grew up using IRC and know all its faults really well and we're trying to fix it."