I don’t like Slack either, but the article isn’t about Slack. It’s about a leader trying to install some product thinking into what I can only assume to be a start-up made up mostly of engineers at the time. Makes you wonder (and perhaps detect a little irony) why sending that email was thought to be useful or necessary at that time in Slack’s product life cycle.
Whether you like Slack or not, they found product-market fit and are objectively more successful than most of us here will ever be. And here’s an artifact that gives you a glimpse into how they managed to do it.
Now how do you plan to reach product-market fit?
How does your strategy differ from “build something great and they will come”?