I concur. I've learned a lot listening and participating in chat rooms, but not all of them are the same. Some are definitely toxic, some are uplifting -- intellectually or otherwise. My personal recipe is once I have a topic in mind, I browse through the channel list, filtering by popularity. In my experience, "toxicity", for the lack of a better term, is proportional to popularity (crowdedness) and mainstreamness. In practical terms, if a channel has a lot of members (150+) that's not a good sign. If it's also a mainstream topic, that's a definite red flag. In my case, I would consider joining that channel a waste of time and energy. If I'm interested in a mainstream topic, sorting the channels by user count will quickly reveal where people go to escape the madness; as channels get big and sickly the interesting and helpful people tend to go to one of the sattelite channels that don't have those problems. As an example, the best channel on Python I found for my purposes had ~5-15 active users per day. I'm especially happy with IRC, because I am intrinsically drawn to more obscure technologies and their channels don't have these problems.

That said, IRC is made by the communities using it. The only, but a significant technological advantage it has over other chat mediums is its minimalism. Barebones chat is much more conducive to technical discussions, than the bloated alternatives, and I think the same applies for other kinds of discussions as well.

Or equivalently you might be praising a protocol for some excellent channel choices (to be accurate, this would be a response to the grand-grandparent comment).

My personal experience suggests that IRC communities are just like other communities, that is, with a right amount of moderation and a right set of users they will survive, otherwise they will fail.