That's not the case either though - many users have bouncers that will sit in the channel the whole time, and you have no idea who might be saving logs or where they might be publishing them. It's the worst of both worlds.
Then I know they're reading.
>and you have no idea who might be saving logs or where they might be publishing them
If I'm in a room with you nothing stops you from telling others what I've told you.
Sure, but I won't have a complete written record like an IRC log, and won't be able to credibly quote.