Can you see how maybe other people might have valid concerns about the effects of a product, and ask for more rigor in the company's processes?

That's perhaps the most tortured analogy I've ever heard. I can't even begin to fathom how you think that's comparable or relevant.

Sounds like it got my point across. You just don’t like the point.

Slack is successful because of marketing, not technical superiority.

I worked at a small company that used Google Talk for office chat, and us developers complained because it was difficult to have a group conversation with. We started using Discord (we were familiar with it and liked the dark theme) and it caught on and we were quite productive with it. Our business types saw it and decided to "formalize" it, so they picked Slack and rolled it out company wide. Most people actually preferred Discord, but the business types preferred Slack (probably mostly because of marketing), and now we're all using Slack.

Now, Slack also didn't royally screw up as it scaled up (outages were rare and transparently reported), which is a credit to the developers and PR people. That being said, just because something is successful doesn't mean it's good; it could be, but that's tangential to the topic at hand.