What you describe is the most natural, effortless way to use Slack. Conversely the design makes it very cumbersome to compose thoughtful, well-formatted respons

What you describe is the most natural, effortless way to use Slack. Conversely the design makes it very cumbersome to compose thoughtful, well-formatted responses. And the more people use the former style, the less value the latter has. So users tend toward spewing out crap rather than having considered discussion, because Slack's system design strongly encourages it. It takes so much cultural pressure, moaning and nagging to use Slack in a high signal-to-noise manner that I'm quite bearish on it's long-term prospects, and applaud OP's effort at building a system designed more for collaboration than shitposting.