As a user, I was very disappointed to see that the gateways must be enabled by the project owner, not by the users themselves. In the end none of the Slack groups I've participated in allowed me to connect via IRC/XMPP.
Slack is an in-company chat product (their slogan is literally “where work happens” [1]) and it was never intended for public groups, which is why all invite automation tools for Slack are third-party. Slack doesn’t want you to use their product as a public chatroom and they try really hard to make that as unattractive as possible.
Given that, “moderation nightmare” is not really a concern for the target audience since if your company needs moderation in its work chat, you have much bigger problems.
